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Organic Chemistry

Additional Problems

Organic ChemistryAdditional Problems

Table of contents
  1. Dedication and Preface
  2. 1 Structure and Bonding
    1. Why This Chapter?
    2. 1.1 Atomic Structure: The Nucleus
    3. 1.2 Atomic Structure: Orbitals
    4. 1.3 Atomic Structure: Electron Configurations
    5. 1.4 Development of Chemical Bonding Theory
    6. 1.5 Describing Chemical Bonds: Valence Bond Theory
    7. 1.6 sp3 Hybrid Orbitals and the Structure of Methane
    8. 1.7 sp3 Hybrid Orbitals and the Structure of Ethane
    9. 1.8 sp2 Hybrid Orbitals and the Structure of Ethylene
    10. 1.9 sp Hybrid Orbitals and the Structure of Acetylene
    11. 1.10 Hybridization of Nitrogen, Oxygen, Phosphorus, and Sulfur
    12. 1.11 Describing Chemical Bonds: Molecular Orbital Theory
    13. 1.12 Drawing Chemical Structures
    14. Chemistry Matters—Organic Foods: Risk versus Benefit
    15. Key Terms
    16. Summary
    17. Additional Problems
  3. 2 Polar Covalent Bonds; Acids and Bases
    1. Why This Chapter?
    2. 2.1 Polar Covalent Bonds and Electronegativity
    3. 2.2 Polar Covalent Bonds and Dipole Moments
    4. 2.3 Formal Charges
    5. 2.4 Resonance
    6. 2.5 Rules for Resonance Forms
    7. 2.6 Drawing Resonance Forms
    8. 2.7 Acids and Bases: The Brønsted–Lowry Definition
    9. 2.8 Acid and Base Strength
    10. 2.9 Predicting Acid–Base Reactions from pKa Values
    11. 2.10 Organic Acids and Organic Bases
    12. 2.11 Acids and Bases: The Lewis Definition
    13. 2.12 Noncovalent Interactions between Molecules
    14. Chemistry Matters—Alkaloids: From Cocaine to Dental Anesthetics
    15. Key Terms
    16. Summary
    17. Additional Problems
  4. 3 Organic Compounds: Alkanes and Their Stereochemistry
    1. Why This Chapter?
    2. 3.1 Functional Groups
    3. 3.2 Alkanes and Alkane Isomers
    4. 3.3 Alkyl Groups
    5. 3.4 Naming Alkanes
    6. 3.5 Properties of Alkanes
    7. 3.6 Conformations of Ethane
    8. 3.7 Conformations of Other Alkanes
    9. Chemistry Matters—Gasoline
    10. Key Terms
    11. Summary
    12. Additional Problems
  5. 4 Organic Compounds: Cycloalkanes and Their Stereochemistry
    1. Why This Chapter?
    2. 4.1 Naming Cycloalkanes
    3. 4.2 Cis–Trans Isomerism in Cycloalkanes
    4. 4.3 Stability of Cycloalkanes: Ring Strain
    5. 4.4 Conformations of Cycloalkanes
    6. 4.5 Conformations of Cyclohexane
    7. 4.6 Axial and Equatorial Bonds in Cyclohexane
    8. 4.7 Conformations of Monosubstituted Cyclohexanes
    9. 4.8 Conformations of Disubstituted Cyclohexanes
    10. 4.9 Conformations of Polycyclic Molecules
    11. Chemistry Matters—Molecular Mechanics
    12. Key Terms
    13. Summary
    14. Additional Problems
  6. 5 Stereochemistry at Tetrahedral Centers
    1. Why This Chapter?
    2. 5.1 Enantiomers and the Tetrahedral Carbon
    3. 5.2 The Reason for Handedness in Molecules: Chirality
    4. 5.3 Optical Activity
    5. 5.4 Pasteur’s Discovery of Enantiomers
    6. 5.5 Sequence Rules for Specifying Configuration
    7. 5.6 Diastereomers
    8. 5.7 Meso Compounds
    9. 5.8 Racemic Mixtures and the Resolution of Enantiomers
    10. 5.9 A Review of Isomerism
    11. 5.10 Chirality at Nitrogen, Phosphorus, and Sulfur
    12. 5.11 Prochirality
    13. 5.12 Chirality in Nature and Chiral Environments
    14. Chemistry Matters—Chiral Drugs
    15. Key Terms
    16. Summary
    17. Additional Problems
  7. 6 An Overview of Organic Reactions
    1. Why This Chapter?
    2. 6.1 Kinds of Organic Reactions
    3. 6.2 How Organic Reactions Occur: Mechanisms
    4. 6.3 Polar Reactions
    5. 6.4 An Example of a Polar Reaction: Addition of HBr to Ethylene
    6. 6.5 Using Curved Arrows in Polar Reaction Mechanisms
    7. 6.6 Radical Reactions
    8. 6.7 Describing a Reaction: Equilibria, Rates, and Energy Changes
    9. 6.8 Describing a Reaction: Bond Dissociation Energies
    10. 6.9 Describing a Reaction: Energy Diagrams and Transition States
    11. 6.10 Describing a Reaction: Intermediates
    12. 6.11 A Comparison Between Biological Reactions and Laboratory Reactions
    13. Chemistry Matters—Where Do Drugs Come From?
    14. Key Terms
    15. Summary
    16. Additional Problems
  8. 7 Alkenes: Structure and Reactivity
    1. Why This Chapter?
    2. 7.1 Industrial Preparation and Use of Alkenes
    3. 7.2 Calculating the Degree of Unsaturation
    4. 7.3 Naming Alkenes
    5. 7.4 Cis–Trans Isomerism in Alkenes
    6. 7.5 Alkene Stereochemistry and the E,Z Designation
    7. 7.6 Stability of Alkenes
    8. 7.7 Electrophilic Addition Reactions of Alkenes
    9. 7.8 Orientation of Electrophilic Additions: Markovnikov’s Rule
    10. 7.9 Carbocation Structure and Stability
    11. 7.10 The Hammond Postulate
    12. 7.11 Evidence for the Mechanism of Electrophilic Additions: Carbocation Rearrangements
    13. Chemistry Matters—Bioprospecting: Hunting for Natural Products
    14. Key Terms
    15. Summary
    16. Additional Problems
  9. 8 Alkenes: Reactions and Synthesis
    1. Why This Chapter?
    2. 8.1 Preparing Alkenes: A Preview of Elimination Reactions
    3. 8.2 Halogenation of Alkenes: Addition of X2
    4. 8.3 Halohydrins from Alkenes: Addition of HO-X
    5. 8.4 Hydration of Alkenes: Addition of H2O by Oxymercuration
    6. 8.5 Hydration of Alkenes: Addition of H2O by Hydroboration
    7. 8.6 Reduction of Alkenes: Hydrogenation
    8. 8.7 Oxidation of Alkenes: Epoxidation and Hydroxylation
    9. 8.8 Oxidation of Alkenes: Cleavage to Carbonyl Compounds
    10. 8.9 Addition of Carbenes to Alkenes: Cyclopropane Synthesis
    11. 8.10 Radical Additions to Alkenes: Chain-Growth Polymers
    12. 8.11 Biological Additions of Radicals to Alkenes
    13. 8.12 Reaction Stereochemistry: Addition of H2O to an Achiral Alkene
    14. 8.13 Reaction Stereochemistry: Addition of H2O to a Chiral Alkene
    15. Chemistry Matters—Terpenes: Naturally Occurring Alkenes
    16. Key Terms
    17. Summary
    18. Summary of Reactions
    19. Additional Problems
  10. 9 Alkynes: An Introduction to Organic Synthesis
    1. Why This Chapter?
    2. 9.1 Naming Alkynes
    3. 9.2 Preparation of Alkynes: Elimination Reactions of Dihalides
    4. 9.3 Reactions of Alkynes: Addition of HX and X2
    5. 9.4 Hydration of Alkynes
    6. 9.5 Reduction of Alkynes
    7. 9.6 Oxidative Cleavage of Alkynes
    8. 9.7 Alkyne Acidity: Formation of Acetylide Anions
    9. 9.8 Alkylation of Acetylide Anions
    10. 9.9 An Introduction to Organic Synthesis
    11. Chemistry Matters—The Art of Organic Synthesis
    12. Key Terms
    13. Summary
    14. Summary of Reactions
    15. Additional Problems
  11. 10 Organohalides
    1. Why This Chapter?
    2. 10.1 Names and Structures of Alkyl Halides
    3. 10.2 Preparing Alkyl Halides from Alkanes: Radical Halogenation
    4. 10.3 Preparing Alkyl Halides from Alkenes: Allylic Bromination
    5. 10.4 Stability of the Allyl Radical: Resonance Revisited
    6. 10.5 Preparing Alkyl Halides from Alcohols
    7. 10.6 Reactions of Alkyl Halides: Grignard Reagents
    8. 10.7 Organometallic Coupling Reactions
    9. 10.8 Oxidation and Reduction in Organic Chemistry
    10. Chemistry Matters—Naturally Occurring Organohalides
    11. Key Terms
    12. Summary
    13. Summary of Reactions
    14. Additional Problems
  12. 11 Reactions of Alkyl Halides: Nucleophilic Substitutions and Eliminations
    1. Why This Chapter?
    2. 11.1 The Discovery of Nucleophilic Substitution Reactions
    3. 11.2 The SN2 Reaction
    4. 11.3 Characteristics of the SN2 Reaction
    5. 11.4 The SN1 Reaction
    6. 11.5 Characteristics of the SN1 Reaction
    7. 11.6 Biological Substitution Reactions
    8. 11.7 Elimination Reactions: Zaitsev’s Rule
    9. 11.8 The E2 Reaction and the Deuterium Isotope Effect
    10. 11.9 The E2 Reaction and Cyclohexane Conformation
    11. 11.10 The E1 and E1cB Reactions
    12. 11.11 Biological Elimination Reactions
    13. 11.12 A Summary of Reactivity: SN1, SN2, E1, E1cB, and E2
    14. Chemistry Matters—Green Chemistry
    15. Key Terms
    16. Summary
    17. Summary of Reactions
    18. Additional Problems
  13. 12 Structure Determination: Mass Spectrometry and Infrared Spectroscopy
    1. Why This Chapter?
    2. 12.1 Mass Spectrometry of Small Molecules: Magnetic-Sector Instruments
    3. 12.2 Interpreting Mass Spectra
    4. 12.3 Mass Spectrometry of Some Common Functional Groups
    5. 12.4 Mass Spectrometry in Biological Chemistry: Time-of-Flight (TOF) Instruments
    6. 12.5 Spectroscopy and the Electromagnetic Spectrum
    7. 12.6 Infrared Spectroscopy
    8. 12.7 Interpreting Infrared Spectra
    9. 12.8 Infrared Spectra of Some Common Functional Groups
    10. Chemistry Matters—X-Ray Crystallography
    11. Key Terms
    12. Summary
    13. Additional Problems
  14. 13 Structure Determination: Nuclear Magnetic Resonance Spectroscopy
    1. Why This Chapter?
    2. 13.1 Nuclear Magnetic Resonance Spectroscopy
    3. 13.2 The Nature of NMR Absorptions
    4. 13.3 Chemical Shifts
    5. 13.4 Chemical Shifts in 1H NMR Spectroscopy
    6. 13.5 Integration of 1H NMR Absorptions: Proton Counting
    7. 13.6 Spin–Spin Splitting in 1H NMR Spectra
    8. 13.7 1H NMR Spectroscopy and Proton Equivalence
    9. 13.8 More Complex Spin–Spin Splitting Patterns
    10. 13.9 Uses of 1H NMR Spectroscopy
    11. 13.10 13C NMR Spectroscopy: Signal Averaging and FT–NMR
    12. 13.11 Characteristics of 13C NMR Spectroscopy
    13. 13.12 DEPT 13C NMR Spectroscopy
    14. 13.13 Uses of 13C NMR Spectroscopy
    15. Chemistry Matters—Magnetic Resonance Imaging (MRI)
    16. Key Terms
    17. Summary
    18. Additional Problems
  15. 14 Conjugated Compounds and Ultraviolet Spectroscopy
    1. Why This Chapter?
    2. 14.1 Stability of Conjugated Dienes: Molecular Orbital Theory
    3. 14.2 Electrophilic Additions to Conjugated Dienes: Allylic Carbocations
    4. 14.3 Kinetic versus Thermodynamic Control of Reactions
    5. 14.4 The Diels–Alder Cycloaddition Reaction
    6. 14.5 Characteristics of the Diels–Alder Reaction
    7. 14.6 Diene Polymers: Natural and Synthetic Rubbers
    8. 14.7 Ultraviolet Spectroscopy
    9. 14.8 Interpreting Ultraviolet Spectra: The Effect of Conjugation
    10. 14.9 Conjugation, Color, and the Chemistry of Vision
    11. Chemistry Matters—Photolithography
    12. Key Terms
    13. Summary
    14. Summary of Reactions
    15. Additional Problems
  16. 15 Benzene and Aromaticity
    1. Why This Chapter?
    2. 15.1 Naming Aromatic Compounds
    3. 15.2 Structure and Stability of Benzene
    4. 15.3 Aromaticity and the Hückel 4n + 2 Rule
    5. 15.4 Aromatic Ions
    6. 15.5 Aromatic Heterocycles: Pyridine and Pyrrole
    7. 15.6 Polycyclic Aromatic Compounds
    8. 15.7 Spectroscopy of Aromatic Compounds
    9. Chemistry Matters—Aspirin, NSAIDs, and COX-2 Inhibitors
    10. Key Terms
    11. Summary
    12. Additional Problems
  17. 16 Chemistry of Benzene: Electrophilic Aromatic Substitution
    1. Why This Chapter?
    2. 16.1 Electrophilic Aromatic Substitution Reactions: Bromination
    3. 16.2 Other Aromatic Substitutions
    4. 16.3 Alkylation and Acylation of Aromatic Rings: The Friedel–Crafts Reaction
    5. 16.4 Substituent Effects in Electrophilic Substitutions
    6. 16.5 Trisubstituted Benzenes: Additivity of Effects
    7. 16.6 Nucleophilic Aromatic Substitution
    8. 16.7 Benzyne
    9. 16.8 Oxidation of Aromatic Compounds
    10. 16.9 Reduction of Aromatic Compounds
    11. 16.10 Synthesis of Polysubstituted Benzenes
    12. Chemistry Matters—Combinatorial Chemistry
    13. Key Terms
    14. Summary
    15. Summary of Reactions
    16. Additional Problems
  18. 17 Alcohols and Phenols
    1. Why This Chapter?
    2. 17.1 Naming Alcohols and Phenols
    3. 17.2 Properties of Alcohols and Phenols
    4. 17.3 Preparation of Alcohols: A Review
    5. 17.4 Alcohols from Carbonyl Compounds: Reduction
    6. 17.5 Alcohols from Carbonyl Compounds: Grignard Reaction
    7. 17.6 Reactions of Alcohols
    8. 17.7 Oxidation of Alcohols
    9. 17.8 Protection of Alcohols
    10. 17.9 Phenols and Their Uses
    11. 17.10 Reactions of Phenols
    12. 17.11 Spectroscopy of Alcohols and Phenols
    13. Chemistry Matters—Ethanol: Chemical, Drug, and Poison
    14. Key Terms
    15. Summary
    16. Summary of Reactions
    17. Additional Problems
  19. 18 Ethers and Epoxides; Thiols and Sulfides
    1. Why This Chapter?
    2. 18.1 Names and Properties of Ethers
    3. 18.2 Preparing Ethers
    4. 18.3 Reactions of Ethers: Acidic Cleavage
    5. 18.4 Cyclic Ethers: Epoxides
    6. 18.5 Reactions of Epoxides: Ring-Opening
    7. 18.6 Crown Ethers
    8. 18.7 Thiols and Sulfides
    9. 18.8 Spectroscopy of Ethers
    10. Chemistry Matters—Epoxy Resins and Adhesives
    11. Key Terms
    12. Summary
    13. Summary of Reactions
    14. Additional Problems
    15. Preview of Carbonyl Chemistry
  20. 19 Aldehydes and Ketones: Nucleophilic Addition Reactions
    1. Why This Chapter?
    2. 19.1 Naming Aldehydes and Ketones
    3. 19.2 Preparing Aldehydes and Ketones
    4. 19.3 Oxidation of Aldehydes and Ketones
    5. 19.4 Nucleophilic Addition Reactions of Aldehydes and Ketones
    6. 19.5 Nucleophilic Addition of H2O: Hydration
    7. 19.6 Nucleophilic Addition of HCN: Cyanohydrin Formation
    8. 19.7 Nucleophilic Addition of Hydride and Grignard Reagents: Alcohol Formation
    9. 19.8 Nucleophilic Addition of Amines: Imine and Enamine Formation
    10. 19.9 Nucleophilic Addition of Hydrazine: The Wolff–Kishner Reaction
    11. 19.10 Nucleophilic Addition of Alcohols: Acetal Formation
    12. 19.11 Nucleophilic Addition of Phosphorus Ylides: The Wittig Reaction
    13. 19.12 Biological Reductions
    14. 19.13 Conjugate Nucleophilic Addition to α,β‑Unsaturated Aldehydes and Ketones
    15. 19.14 Spectroscopy of Aldehydes and Ketones
    16. Chemistry Matters—Enantioselective Synthesis
    17. Key Terms
    18. Summary
    19. Summary of Reactions
    20. Additional Problems
  21. 20 Carboxylic Acids and Nitriles
    1. Why This Chapter?
    2. 20.1 Naming Carboxylic Acids and Nitriles
    3. 20.2 Structure and Properties of Carboxylic Acids
    4. 20.3 Biological Acids and the Henderson–Hasselbalch Equation
    5. 20.4 Substituent Effects on Acidity
    6. 20.5 Preparing Carboxylic Acids
    7. 20.6 Reactions of Carboxylic Acids: An Overview
    8. 20.7 Chemistry of Nitriles
    9. 20.8 Spectroscopy of Carboxylic Acids and Nitriles
    10. Chemistry Matters—Vitamin C
    11. Key Terms
    12. Summary
    13. Summary of Reactions
    14. Additional Problems
  22. 21 Carboxylic Acid Derivatives: Nucleophilic Acyl Substitution Reactions
    1. Why This Chapter?
    2. 21.1 Naming Carboxylic Acid Derivatives
    3. 21.2 Nucleophilic Acyl Substitution Reactions
    4. 21.3 Reactions of Carboxylic Acids
    5. 21.4 Chemistry of Acid Halides
    6. 21.5 Chemistry of Acid Anhydrides
    7. 21.6 Chemistry of Esters
    8. 21.7 Chemistry of Amides
    9. 21.8 Chemistry of Thioesters and Acyl Phosphates: Biological Carboxylic Acid Derivatives
    10. 21.9 Polyamides and Polyesters: Step-Growth Polymers
    11. 21.10 Spectroscopy of Carboxylic Acid Derivatives
    12. Chemistry Matters—β-Lactam Antibiotics
    13. Key Terms
    14. Summary
    15. Summary of Reactions
    16. Additional Problems
  23. 22 Carbonyl Alpha-Substitution Reactions
    1. Why This Chapter?
    2. 22.1 Keto–Enol Tautomerism
    3. 22.2 Reactivity of Enols: α-Substitution Reactions
    4. 22.3 Alpha Halogenation of Aldehydes and Ketones
    5. 22.4 Alpha Bromination of Carboxylic Acids
    6. 22.5 Acidity of Alpha Hydrogen Atoms: Enolate Ion Formation
    7. 22.6 Reactivity of Enolate Ions
    8. 22.7 Alkylation of Enolate Ions
    9. Chemistry Matters—Barbiturates
    10. Key Terms
    11. Summary
    12. Summary of Reactions
    13. Additional Problems
  24. 23 Carbonyl Condensation Reactions
    1. Why This Chapter?
    2. 23.1 Carbonyl Condensations: The Aldol Reaction
    3. 23.2 Carbonyl Condensations versus Alpha Substitutions
    4. 23.3 Dehydration of Aldol Products: Synthesis of Enones
    5. 23.4 Using Aldol Reactions in Synthesis
    6. 23.5 Mixed Aldol Reactions
    7. 23.6 Intramolecular Aldol Reactions
    8. 23.7 The Claisen Condensation Reaction
    9. 23.8 Mixed Claisen Condensations
    10. 23.9 Intramolecular Claisen Condensations: The Dieckmann Cyclization
    11. 23.10 Conjugate Carbonyl Additions: The Michael Reaction
    12. 23.11 Carbonyl Condensations with Enamines: The Stork Enamine Reaction
    13. 23.12 The Robinson Annulation Reaction
    14. 23.13 Some Biological Carbonyl Condensation Reactions
    15. Chemistry Matters—A Prologue to Metabolism
    16. Key Terms
    17. Summary
    18. Summary of Reactions
    19. Additional Problems
  25. 24 Amines and Heterocycles
    1. Why This Chapter?
    2. 24.1 Naming Amines
    3. 24.2 Structure and Properties of Amines
    4. 24.3 Basicity of Amines
    5. 24.4 Basicity of Arylamines
    6. 24.5 Biological Amines and the Henderson–Hasselbalch Equation
    7. 24.6 Synthesis of Amines
    8. 24.7 Reactions of Amines
    9. 24.8 Reactions of Arylamines
    10. 24.9 Heterocyclic Amines
    11. 24.10 Spectroscopy of Amines
    12. Chemistry Matters—Green Chemistry II: Ionic Liquids
    13. Key Terms
    14. Summary
    15. Summary of Reactions
    16. Additional Problems
  26. 25 Biomolecules: Carbohydrates
    1. Why This Chapter?
    2. 25.1 Classification of Carbohydrates
    3. 25.2 Representing Carbohydrate Stereochemistry: Fischer Projections
    4. 25.3 D,L Sugars
    5. 25.4 Configurations of the Aldoses
    6. 25.5 Cyclic Structures of Monosaccharides: Anomers
    7. 25.6 Reactions of Monosaccharides
    8. 25.7 The Eight Essential Monosaccharides
    9. 25.8 Disaccharides
    10. 25.9 Polysaccharides and Their Synthesis
    11. 25.10 Some Other Important Carbohydrates
    12. Chemistry Matters—Sweetness
    13. Key Terms
    14. Summary
    15. Summary of Reactions
    16. Additional Problems
  27. 26 Biomolecules: Amino Acids, Peptides, and Proteins
    1. Why This Chapter?
    2. 26.1 Structures of Amino Acids
    3. 26.2 Amino Acids and the Henderson–Hasselbalch Equation: Isoelectric Points
    4. 26.3 Synthesis of Amino Acids
    5. 26.4 Peptides and Proteins
    6. 26.5 Amino Acid Analysis of Peptides
    7. 26.6 Peptide Sequencing: The Edman Degradation
    8. 26.7 Peptide Synthesis
    9. 26.8 Automated Peptide Synthesis: The Merrifield Solid-Phase Method
    10. 26.9 Protein Structure
    11. 26.10 Enzymes and Coenzymes
    12. 26.11 How Do Enzymes Work? Citrate Synthase
    13. Chemistry Matters—The Protein Data Bank
    14. Key Terms
    15. Summary
    16. Summary of Reactions
    17. Additional Problems
  28. 27 Biomolecules: Lipids
    1. Why This Chapter?
    2. 27.1 Waxes, Fats, and Oils
    3. 27.2 Soap
    4. 27.3 Phospholipids
    5. 27.4 Prostaglandins and Other Eicosanoids
    6. 27.5 Terpenoids
    7. 27.6 Steroids
    8. 27.7 Biosynthesis of Steroids
    9. Chemistry Matters—Saturated Fats, Cholesterol, and Heart Disease
    10. Key Terms
    11. Summary
    12. Additional Problems
  29. 28 Biomolecules: Nucleic Acids
    1. Why This Chapter?
    2. 28.1 Nucleotides and Nucleic Acids
    3. 28.2 Base Pairing in DNA
    4. 28.3 Replication of DNA
    5. 28.4 Transcription of DNA
    6. 28.5 Translation of RNA: Protein Biosynthesis
    7. 28.6 DNA Sequencing
    8. 28.7 DNA Synthesis
    9. 28.8 The Polymerase Chain Reaction
    10. Chemistry Matters—DNA Fingerprinting
    11. Key Terms
    12. Summary
    13. Additional Problems
  30. 29 The Organic Chemistry of Metabolic Pathways
    1. Why This Chapter?
    2. 29.1 An Overview of Metabolism and Biochemical Energy
    3. 29.2 Catabolism of Triacylglycerols: The Fate of Glycerol
    4. 29.3 Catabolism of Triacylglycerols: β-Oxidation
    5. 29.4 Biosynthesis of Fatty Acids
    6. 29.5 Catabolism of Carbohydrates: Glycolysis
    7. 29.6 Conversion of Pyruvate to Acetyl CoA
    8. 29.7 The Citric Acid Cycle
    9. 29.8 Carbohydrate Biosynthesis: Gluconeogenesis
    10. 29.9 Catabolism of Proteins: Deamination
    11. 29.10 Some Conclusions about Biological Chemistry
    12. Chemistry Matters—Statin Drugs
    13. Key Terms
    14. Summary
    15. Additional Problems
  31. 30 Orbitals and Organic Chemistry: Pericyclic Reactions
    1. Why This Chapter?
    2. 30.1 Molecular Orbitals of Conjugated Pi Systems
    3. 30.2 Electrocyclic Reactions
    4. 30.3 Stereochemistry of Thermal Electrocyclic Reactions
    5. 30.4 Photochemical Electrocyclic Reactions
    6. 30.5 Cycloaddition Reactions
    7. 30.6 Stereochemistry of Cycloadditions
    8. 30.7 Sigmatropic Rearrangements
    9. 30.8 Some Examples of Sigmatropic Rearrangements
    10. 30.9 A Summary of Rules for Pericyclic Reactions
    11. Chemistry Matters—Vitamin D, the Sunshine Vitamin
    12. Key Terms
    13. Summary
    14. Additional Problems
  32. 31 Synthetic Polymers
    1. Why This Chapter?
    2. 31.1 Chain-Growth Polymers
    3. 31.2 Stereochemistry of Polymerization: Ziegler–Natta Catalysts
    4. 31.3 Copolymers
    5. 31.4 Step-Growth Polymers
    6. 31.5 Olefin Metathesis Polymerization
    7. 31.6 Intramolecular Olefin Metathesis
    8. 31.7 Polymer Structure and Physical Properties
    9. Chemistry Matters—Degradable Polymers
    10. Key Terms
    11. Summary
    12. Additional Problems
  33. A | Nomenclature of Polyfunctional Organic Compounds
  34. B | Acidity Constants for Some Organic Compounds
  35. C | Glossary
  36. D | Periodic Table
  37. Answer Key
    1. Chapter 1
    2. Chapter 2
    3. Chapter 3
    4. Chapter 4
    5. Chapter 5
    6. Chapter 6
    7. Chapter 7
    8. Chapter 8
    9. Chapter 9
    10. Chapter 10
    11. Chapter 11
    12. Chapter 12
    13. Chapter 13
    14. Chapter 14
    15. Chapter 15
    16. Chapter 16
    17. Chapter 17
    18. Chapter 18
    19. Chapter 19
    20. Chapter 20
    21. Chapter 21
    22. Chapter 22
    23. Chapter 23
    24. Chapter 24
    25. Chapter 25
    26. Chapter 26
    27. Chapter 27
    28. Chapter 28
    29. Chapter 29
    30. Chapter 30
    31. Chapter 31
  38. Index

21 • Additional Problems

21 • Additional Problems

Visualizing Chemistry

Problem 21-27
Name the following compounds:
(a)
Ball-and-stick model depicts four-carbon chain with N, N-dimethylamine, and methyl groups attached to first and third carbon. Black, gray, blue, and red spheres represent carbon, hydrogen, nitrogen, and oxygen, respectively.
(b)
The ball-and-stick model shows a carbonyl group with a benzene ring attached to one side and a four carbon chain bearing a methyl group on C3 on the other side.
Problem 21-28
How would you prepare the following compounds starting with an appropriate carboxylic acid and any other reagents needed? (reddish brown = Br.)
(a)
The ball-and-stick model shows a carbonyl group with an ortho substituted bromobenzene ring attached to one side and an isopropyl group on the other side.
(b)
Ball-and-stick model shows cyclopentane ring with a C H 2 C O N H 2 group as a side chain. The blue and reddish-brown spheres represent nitrogen and bromine, respectively.
Problem 21-29

The following structure represents a tetrahedral alkoxide-ion intermediate formed by addition of a nucleophile to a carboxylic acid derivative. Identify the nucleophile, the leaving group, the starting acid derivative, and the ultimate product (green = Cl).

Ball-and-stick model shows a five-carbon alkoxide chain where ammonia and chlorine are attached to the carbonyl carbon. The fourth and fifth carbons are double-bonded, with a methyl group on the fourth.
Problem 21-30

Electrostatic potential maps of a typical amide (acetamide) and an acyl azide (acetyl azide) are shown. Which of the two do you think is more reactive in nucleophilic acyl substitution reactions? Explain.

The electrostatic potential map and structure of acetamide and acetyl azide. The azide has a carbonyl group with a methyl group on one side and a chain of three nitrogen atoms on the other side. The nitrogens are double bonded to each other.

Mechanism Problems

Problem 21-31
Predict the product(s) and write the mechanism for the following reactions:
(a)
The reaction between ethyl propionate and ethyl amine in the presence of pyridine gives unknown products depicted by a question mark.
(b)
The reaction between a five-membered ring containing two carbonyl groups with an oxygen atom between them and sodium methoxide gives unknown products depicted by a question mark.
Problem 21-32
Predict the product(s) and write the mechanism for the following reactions:
(a)
The reaction between cyclopentane carboxylic acid and thionyl chloride gives unknown products depicted by a question mark.
(b)
The reaction of but-2-enoic acid with thionyl chloride giving unknown products depicted by a question mark.
Problem 21-33
Predict the product(s) and write the mechanism for each of the following reactions:
(a)
The reaction of ethyl-3-methyl butanoate with aqueous acid gives an unknown product depicted by a question mark.
(b)
The reaction of but-2-enoic acid with hydrochloric acid catalyst in methanol gives an unknown product depicted by a question mark.
Problem 21-34
Predict the product(s) and write the mechanism for the following reactions:
(a)
The reaction of an ester with two equivalents of phenyl magnesium bromide in ether, followed by treatment with acid gives an unknown product depicted by a question mark.
(b)
The reaction of a four membered ring contaning a carbonyl group with an oxygen atom next to it with two equivalents of ethyl magnesium bromide in ether followed treatment with acid gives an unknown product depicted by a question mark.
Problem 21-35

Pivalic mixed anhydrides are often used to form amide bonds between amino acids. Unlike with a symmetrical anhydride, this reaction is highly regioselective, with the nucleophile adding only to the amino-acid carbonyl. Provide the complete mechanism for the following reaction and explain the regioselectivity.

Reaction between pivaloyl or amino acid mixed anhydride with another amine compound forming amide-bond containing compound and 2,2-dimethylpropanoic acid. The amine group in anhydride is B o c protected.
Problem 21-36
When 4-dimethylaminopyridine (DMAP) is added in catalytic amounts to acetic anhydride and an alcohol, it significantly increases the rate of ester formation. The process begins with a reaction between acetic anhydride and DMAP to form a highly reactive acetylpyridinium intermediate that is more reactive than acetic anhydride itself. Propose a mechanism for this process that includes the formation and reaction of the acetylpyridinium intermediate.
Problem 21-37

Fats are biosynthesized from glycerol 3-phosphate and fatty-acyl CoA’s by a reaction sequence that begins with the following step. Show the mechanism of the reaction.

The reaction between glycerol-3-phosphate and fatty-acyl coenzyme A in the presence of glycerol-3-phosphate acyltransferase to form 1-acylglycerol-3-phosphate. The glycerol-3-phosphate contains three-carbon vertical chain in which hydroxyl is replaced by phosphate.
Problem 21-38

Treatment of an α-amino acid with DCC yields a 2,5-diketopiperazine. Propose a mechanism.

The reaction shows the conversion of an alpha-amino acid to a 2,5-diketopiperazine using D C C as a reagent.
Problem 21-39

Succinic anhydride yields the cyclic imide succinimide when heated with ammonium chloride at 200 °C. Propose a mechanism for this reaction. Why do you suppose such a high reaction temperature is required?

The reaction shows the conversion of dihydrofuran-2, 5-dione to an amide by heating at two-hundred degrees Celcius in the presence of ammonium chloride.
Problem 21-40

The hydrolysis of a biological thioester to the corresponding carboxylate is often more complex than the overall result might suggest. The conversion of succinyl CoA to succinate in the citric acid cycle, for instance, occurs by initial formation of an acyl phosphate, followed by reaction with guanosine diphosphate (GDP, a relative of adenosine diphosphate [ADP]) to give succinate and guanosine triphosphate (GTP, a relative of ATP). Suggest mechanisms for both steps.

Conversion of succinyl coenzyme A to succinate and G T P. The process involves use of hydrogen phosphate to make an acyl phosphate, followed by reaction with guanosine diphosphate.
Problem 21-41

One step in the gluconeogenesis pathway for the biosynthesis of glucose is the partial reduction of 3-phosphoglycerate to give glyceraldehyde 3-phosphate. The process occurs by phosphorylation with ATP to give 1,3-bisphosphoglycerate, reaction with a thiol group on the enzyme to give an enzyme-bound thioester, and reduction with NADH. Suggest mechanisms for all three reactions.

The reaction shows the enzyme-catalyzed conversion of 3-phosphoglycerate to glyceraldehyde-3-phosphate. 1,3-Bisphosphoglycerate and an enzyme-bound thioester are formed as intermediates.
Problem 21-42

Bacteria typically develop a resistance to penicillins and other β-lactam antibiotics (see Chemistry Matters at the end of this chapter) due to bacterial synthesis of β-lactamase enzymes. Tazobactam, however, is able to inhibit the activity of the β-lactamase by trapping it, thereby preventing a resistance from developing.

Reaction of beta-lactamase and tazobactam generates a  trapped beta-lactamase. The reaction proceeds through multiple steps. Tazobactam contain a four-membered lactam ring.
(a)
The first step in trapping is reaction of a hydroxyl group on the β-lactamase to open the β-lactam ring of tazobactam. Show the mechanism.
(b)
The second step is opening the sulfur-containing ring in tazobactam to give an acyclic imine intermediate. Show the mechanism.
(c)
Cyclization of the imine intermediate gives the trapped β-lactamase product. Show the mechanism.
Problem 21-43

The following reaction, called the benzilic acid rearrangement, takes place by typical carbonyl-group reactions. Propose a mechanism (Ph = phenyl).

Benzil is converted to a benzylic acid by treatment first with aqueous sodium hydroxide and then with acid. Benzil is a dicarbonyl compound with two carbonyl groups joined to one another and a benzene ring on each carbonyl. The reaction occurs by a rearrangement.
Problem 21-44

In the iodoform reaction, a triiodomethyl ketone reacts with aqueous NaOH to yield a carboxylate ion and iodoform (triiodomethane). Propose a mechanism for this reaction.

A triiodomethyl ketone is converted to a carbozylate ion by treatment with base and then acid. Triiodomethane is a byproduct.

Naming Carboxylic Acid Derivatives

Problem 21-45
Give IUPAC names for the following compounds:
(a)
The structure shows a substituted benzamide where a methyl group is attached to the para position in the benzene ring.
(b)
The structure shows six-carbon chain where C 1 is a carbonyl group with a chlorine atom attached to it. There is a double bond between C2 and C3 and an ethyl group on C4.
(c)
The structure shows a four-carbon chain where C 1 and C 4 are carbonyl groups. A methoxy group is also attached to each carbonyl carbon.
(d)
The structure shows a benzene ring attached to a three-carbon side chain, the third carbon along the chain being a carbonyl group to which an oxygen and then an isopropyl group are also attached.
(e)
The structure shows an amide with a four-carbon chain where the carbonyl carbon at C 1 is attached to an N-methyl amine. A bromine atom is attached to C 3.
(f)
The structure shows a cyclopentene ring with a methoxycarbonyl group attached to one of the carbons of the double bond.
(g)
The structure shows an ester where the carbonyl carbon is attached to a benzene ring on one side and, on the other side, to an oxygen itself attached to a benzene ring.
(h)
The structure shows a thioester where a benzene ring is attached to a central carbonyl carbon. A sulfur atom bound to an isopropyl group is also attached to the carbonyl carbon.
Problem 21-46
Draw structures corresponding to the following names:
(a)
p-Bromophenylacetamide
(b)
m-Benzoylbenzamide
(c)
2,2-Dimethylhexanamide
(d)
Cyclohexyl cyclohexanecarboxylate
(e)
Ethyl 2-cyclobutenecarboxylate
(f)
Succinic anhydride
Problem 21-47
Draw and name compounds that meet the following descriptions:
(a)
Three acid chlorides having the formula C6H9ClO
(b)
Three amides having the formula C7H11NO

Nucleophilic Acyl Substitution Reactions

Problem 21-48
Predict the product, if any, of reaction between propanoyl chloride and the following reagents:
(a)
Li(Ph)2Cu in ether
(b)
LiAlH4, then H3O+
(c)
CH3MgBr, then H3O+
(d)
H3O+
(e)
Cyclohexanol
(f)
Aniline
(g)
CH3CO2 Na+
Problem 21-49
Answer Problem 21-48 for reaction of the listed reagents with methyl propanoate.
Problem 21-50
Answer Problem 21-48 for reaction of the listed reagents with propanamide.
Problem 21-51
What product would you expect to obtain from Grignard reaction of an excess of phenylmagnesium bromide with dimethyl carbonate, CH3OCO2CH3?
Problem 21-52
How might you prepare the following compounds from butanoic acid?
(a)
1-Butanol
(b)
Butanal
(c)
1-Bromobutane
(d)
Pentanenitrile
(e)
1-Butene
(f)
N-Methylpentanamide
(g)
2-Hexanone
(h)
Butylbenzene
(i)
Butanenitrile
Problem 21-53
Predict the product(s) of the following reactions:
(a)
The reaction of ethyl cyclohexanecarboxylate with ethylmagnesium bromide followed by treatment with acid to give an unknown product, denoted by a question mark.
(b)
The reaction of methyl-4-methylpentanoate with D I B A H followe by treatment with acid to give an unknown product, denoted by a question mark.
(c)
The reaction of cyclopentanecarbonyl chloride with methyl amine to give an unknown product, denoted by a question mark.
(d)
The reaction of 2-methylcyclohexane carboxylic acid with methanol in the presence of sulfuric acid to give an unknown product, denoted by a question mark.
(e)
The reaction of methyl-3-methylpent-4-enoate with lithium aluminum hydride followed by treatment with acid to give a unknown product, denoted by a question mark.
(f)
The reaction of cyclohexanol with acetic anhydride in pyridine to form an unknown product, denoted by a question mark.
(g)
The reaction of 2-methylbenzamide with lithium aluminum hydride and then water to give an unknown product, denoted by a question mark.
(h)
The reaction of 2-(2-bromophenyl)acetic acid with thionyl chloride to form an unknown product, denoted by a question mark.
Problem 21-54

The following reactivity order has been found for the saponification of alkyl acetates by aqueous NaOH. Explain.

CH3CO2CH3 > CH3CO2CH2CH3 > CH3CO2CH(CH3)2 > CH3CO2C(CH3)3

Problem 21-55
Explain the observation that attempted Fischer esterification of 2,4,6-trimethylbenzoic acid with methanol and HCl is unsuccessful. No ester is obtained, and the acid is recovered unchanged. What alternative method of esterification might be successful?
Problem 21-56
Outline methods for the preparation of acetophenone (phenyl methyl ketone) starting from the following:
(a)
Benzene
(b)
Bromobenzene
(c)
Methyl benzoate
(d)
Benzonitrile
(e)
Styrene
Problem 21-57
Treatment of 5-aminopentanoic acid with DCC (dicyclohexylcarbodiimide) yields a lactam. Show the structure of the product and the mechanism of the reaction.
Problem 21-58
When ethyl benzoate is heated in methanol containing a small amount of HCl, methyl benzoate is formed. Propose a mechanism for the reaction.
Problem 21-59

tert-Butoxycarbonyl azide, a reagent used in protein synthesis, is prepared by treating tert-butoxycarbonyl chloride with sodium azide. Propose a mechanism for this reaction.

The reaction of tert-butyl chloroformate with sodium azide forming an azide derivative in which the chlorine atom is replaced by an N 3 (azide) group at the carbonyl carbon.

Step-Growth Polymers

Problem 21-60

The step-growth polymer nylon 6 is prepared from caprolactam. The reaction involves initial reaction of caprolactam with water to give an intermediate open-chain amino acid, followed by heating to form the polymer. Propose mechanisms for both steps, and show the structure of nylon 6.

The structure of caprolactam comprises of a seven-membered ring containing a carbonyl group attached to an N H group.
Problem 21-61

Qiana, a polyamide fiber with a silky texture, has the following structure. What are the monomer units used in the synthesis of Qiana?

Qiana has a repeating unit that comprises of a dicarbonyl group, an amide bond, and two methylene linked cyclohexane rings.
Problem 21-62

What is the structure of the polymer produced by treatment of β-propiolactone with a small amount of hydroxide ion?

The structure of beta-propiolactone comprises of a four-membered ring with a carbonyl group linked to an oxygen atom in the ring.
Problem 21-63

Polyimides with the structure shown are used as coatings on glass and plastics to improve scratch resistance. How would you synthesize a polyimide? (See Problem 21-39.)

Polyimide structure in parentheses with subscript n shows benzene fused between two cyclopentane with N and two carbonyls. Cyclopentane ring is single-bonded to another benzene on right with free bond.

Spectroscopy

Problem 21-64
How would you distinguish spectroscopically between the following isomer pairs? Tell what differences you would expect to see.
(a)
N-Methylpropanamide and N,N-dimethylacetamide
(b)
5-Hydroxypentanenitrile and cyclobutanecarboxamide
(c)
4-Chlorobutanoic acid and 3-methoxypropanoyl chloride
(d)
Ethyl propanoate and propyl acetate
Problem 21-65

Propose a structure for a compound, C4H7ClO2, that has the following IR and 1H NMR spectra:

The I R spectrum of a compound of molecular formula C 4 H 7 C l O 2 shows peaks at 2900 and 1750 wavenumbers as well as several peaks between 1500 and 700 wavenumbers. The proton N M R spectrum shows three signals, a doublet at 1.69, a singlet at 3.79, and a quartet at 4.41 p p m. The signals integrate as 3, 3, and 1 respectively.
Problem 21-66
Assign structures to compounds with the following 1H NMR spectra:
(a)

C4H7ClO

IR: 1810 cm–1

The proton NMR spectrum of a compound of molecular formula C 4 H 7 C l O shows signals at 0 (T M S), 1.00 (triplet of integral 1.5), 1.75 (quartet of integral 1), and 2.86 (triplet of integral 1) p p m.
(b)

C5H7NO2

IR: 2250, 1735 cm–1

The proton NMR spectrum of a compound of molecular formula C 5 H 7 N O 2 show signals at 0 (T M S), 1.32 (triplet of integral 1.5), 3.51 (singlet of integral 1), and 4.27 (quartet of integral 1) p p m.

General Problems

Problem 21-67

The following reactivity order has been found for the basic hydrolysis of p-substituted methyl benzoates:

Y=NO2 > Br > H > CH3 > OCH3

How can you explain this reactivity order? Where would you expect Y=C N, Y=CHO, and Y=NH2 to be in the reactivity list?

Reaction of a para-substituted methyl benzoate with aqueous base to give the corresponding carboxylate ion and methanol. The substitutent at the para position is represented by the letter Y.
Problem 21-68

When a carboxylic acid is dissolved in isotopically labeled water, the label rapidly becomes incorporated into both oxygen atoms of the carboxylic acid. Explain.

The reaction of a carboxylic acid with isotopically labeled water gives an isotopically labelled carboxylic acid in which both oxygen atoms of the carboxylic acid group are labeled.
Problem 21-69
We said in Section 21.6 that mechanistic studies on ester hydrolysis have been carried out using ethyl propanoate labeled with 18O in the ether-like oxygen. Assume that 18O-labeled acetic acid is your only source of isotopic oxygen, and then propose a synthesis of the labeled ethyl propanoate.
Problem 21-70

Treatment of a carboxylic acid with trifluoroacetic anhydride leads to an unsymmetrical anhydride that rapidly reacts with alcohol to give an ester.

The reaction of a carboxylic acid with trifluoroacetic anhydride generates a mixed anhydride which, upon treatment with an alcohol gives an ester and trifluroacetic acid.
(a)
Propose a mechanism for formation of the unsymmetrical anhydride.
(b)
Why is the unsymmetrical anhydride unusually reactive?
(c)
Why does the unsymmetrical anhydride react as indicated rather than giving a trifluoroacetate ester plus carboxylic acid?
Problem 21-71

Butacetin is an analgesic (pain-killing) agent that is synthesized commercially from p-fluoronitrobenzene. Propose a synthesis.

The structure of butacetin comprises of a para-substituted benzene ring with a carbonyl group attached to a tertiary butyl group as one substituent, and, as the other, an N H group attached to a carbonyl itself attached to a methyl group.
Problem 21-72

Phenyl 4-aminosalicylate is a drug used in the treatment of tuberculosis. Propose a synthesis of this compound starting from 4-nitrosalicylic acid.

The reaction of 4-nitrosalicylic acid to form phenyl-4-aminosalicylate using unknown reagents, denoted by a question mark.
Problem 21-73

N,N-Diethyl-m-toluamide (DEET) is the active ingredient in many insect-repellent preparations. How might you synthesize this substance from m-bromotoluene?

The structure of N, N-diethyl-m-toluamide comrpises of a benzene ring with a carbonyl carbon attached and a methyl group in the meta position. The carbonyl group is also attached to a diethylamine group.
Problem 21-74

Tranexamic acid, a drug useful against blood clotting, is prepared commercially from p-methylbenzonitrile. Formulate the steps likely to be used in the synthesis. (Don’t worry about cis–trans isomers; heating to 300 °C interconverts the isomers.)

The structure of tranexamic acid comprises of a cyclohexane ring wedge-bonded to a carboxylic acid group and dash-bonded to hydrogen at C 1, and wedge-bonded to hydrogen and dash-bonded to methylamine at C 4.
Problem 21-75

One frequently used method for preparing methyl esters is by reaction of carboxylic acids with diazomethane, CH2N2.

The reaction of benzoic acid and diazomethane gives methyl benzoate and molecular nitrogen.

The reaction occurs in two steps: (1) protonation of diazomethane by the carboxylic acid to yield methyldiazonium ion, CH3N2+, plus a carboxylate ion; and (2) reaction of the carboxylate ion with CH3N2+.

(a)
Draw two resonance structures of diazomethane, and account for step 1.
(b)
What kind of reaction occurs in step 2?
Problem 21-76
Draw the structure of the polymer you would expect to obtain from reaction of dimethyl terephthalate with a triol such as glycerol. What structural feature would this new polymer have that was not present in Dacron (Table 21.2)? How do you think this new feature might affect the properties of the polymer?
Problem 21-77
Assign structures to compounds with the following 1H NMR spectra:
(a)

C5H10O2

IR: 1735 cm–1

The proton NMR spectrum of a compound of molecular formula C 5 H 10 O 2 shows signals at 0 (T M S), 1.22 (doublet of integral 6), 2.1 (singlet of integral 3), and 4.99 (septet of integral 1) p p m.
(b)

C11H12O2

IR: 1710 cm–1

The proton NMR spectrum of a compound of molecular formula C 1 1 H 1 2 O 2 shows signals at 0 (T M S), 1.32 (triplet of integral 3), 4.24 (quartet of integral 2), 6.41 (doublet of integral 1), 7.36 (multiplet of integral 3), 7.49 (multiplet of integral 2), and 7.68 (doublet of integral 1) p p m.
Problem 21-78
Propose structures for compounds with the following 1H NMR spectra:
(a)

C5H9ClO2

IR: 1735 cm–1

The proton N M R spectrum of a compound of molecular formula C 5 H 9 C l O 2 shows peaks at 0 (T M S), 1.26 (triplet of integral 1.5), 2.77 (triplet of integral 1), 3.76 (triplet of integral 1), and 4.19 (quartet of integral 1) p p m.
(b)

C7H12O4

IR: 1735 cm–1

The proton NMR spectrum of a compound of molecular formula C 7 H 1 2 O 4 shows signals at 0 (T M S), 1.27 (triplet of integral 3), 3.34 (singlet of integral 1), and 4.20 (quartet of integral 2) p p m
Problem 21-79

Propose a structure for the compound with the formula C19H9NO2 and the following IR and NMR spectra

The I R spectrum of a compound of molecular formula C 9 H 9 N O 2 shows peaks ranging from 400 to 3000 wavenumbers, signals at 2700 to 2900 and a sharp signal at 2250 wavenumebrs are notable. A strong peak at 1724 wavenumbers is highlighted. The proton N M R spectrum of a compound of molecular formula C 9 H 9 N O 2 shows signals at 1.5 (triplet of integral 3), 4.5 (quartet of integral 2), 7.8 (doublet of integral 2), and 8.2 (doublet of integral 2) p p m. The 13 carbon N M R spectrum of a compound of molecular formula C 9 H 9 N O 2 shows signals at 0, 16, 62, and 163 p p m along with a set of three signals between 115 and 120  p p m and another set of three signals between120 and 130 p p m.
Problem 21-80

Draw the structure of the compound that produced the following spectra. The infrared spectrum has strong bands at 1720 and 1738 cm–1.

The proton N M R spectrum of a compound of molecular formula C 7 H 12 O 3 shows signals at 1.25 (triplet of integral 3), 2.2 (singlet of integral 3), 2.6 (triplet of integral 2), 2.75 (triplet of integral 2), and 4.15 (quartet of integral 2) p p m.
Problem 21-81
When an amide is formed from an acid chloride or an anhydride, two equivalents of base are required. However, when an ester is used as the starting material, only one equivalent of base is needed. Explain this reactivity in terms of basicity of the leaving groups.
Problem 21-82

Epoxy adhesives are prepared in two steps. SN2 reaction of the disodium salt of bisphenol A with epichlorohydrin forms a “prepolymer,” which is then “cured” by treatment with a triamine such as H2NCH2CH2NHCH2CH2NH2.

The reaction of Bisphenol A with epichlorohydrin to form a polymer termed as

Draw structures to show how addition of the triamine results in a strengthening of the polymer.

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