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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

24 • Additional Problems

24 • Additional Problems

Visualizing Chemistry

Problem 24-26
Name the following amines, and identify each as primary, secondary, or tertiary:
(a)
A ball-and-stick model of nitrogen bonded to hydrogen, methyl, and isopropyl groups.
(b)
A ball-and-stick model of cyclopentane with methyl and N H 2 substituents on adjacent carbons.
(c)
A ball-and-stick model of nitrogen bonded to a benzene ring, hydrogen, and an isopropyl group
Problem 24-27

The following compound contains three nitrogen atoms. Rank them in order of increasing basicity.

A ball-and-stick model of a large molecule with different functional groups. Black, grey, red, and blue spheres represent carbon, hydrogen, oxygen, and nitrogen.
Problem 24-28

Name the following amine, including R,S stereochemistry, and draw the product of its reaction with excess iodomethane followed by heating with Ag2O (Hofmann elimination). Is the stereochemistry of the alkene product Z or E? Explain.

A ball-and-stick model of a three-carbon chain with benzene rings on C 1 and C 2, and an N H 2 group on C 1.
Problem 24-29

Which nitrogen atom in the following compound is most basic? Explain.

A ball-and-stick model of a large molecule with different functional groups. Black, grey, and blue spheres represent carbon, hydrogen, and nitrogen.

Mechanism Problems

Problem 24-30
Predict the product(s) and write the mechanism for each of the following reactions:
(a)
1-(Bromomethyl)-2-methylbenzene reacts with sodium phthalimide, then hydroxide ion and water to form an unknown product represented by a question mark.
(b)
1-Chloro-3-methylbutane reacts with sodium phthalimide, then hydroxide ion and water to form an unknown product represented by a question mark.
Problem 24-31
Predict the product(s) and write the mechanism for each of the following reactions:
(a)
2-Methyl-1-phenylpropan-1-one reacts with dimethylamine in the presence of sodium borohydride and ethanol to form an unknown product represented by a question mark.
(b)
(1 R,4 S)-Bicyclo[2.2.1]heptan-2-one reacts with pyrrolidine in the presence of sodium borohydride and ethanol to form an unknown product represented by a question mark.
Problem 24-32
Predict the product(s) and write the mechanism for each of the following reactions:
(a)
3-Methylbutanamide reacts with bromine, sodium hydroxide, and water to form an unknown product represented by a question mark.
(b)
Cyclopentanecarboxamide reacts with bromine, sodium hydroxide, and water to form an unknown product represented by a question mark.
(c)
2-Methoxyacetamide reacts with bromine, sodium hydroxide, and water to form an unknown product represented by a question mark.
(d)
2,3-Dihydro-1H-indene-2-carboxamide reacts with bromine, sodium hydroxide, and water to form an unknown product represented by a question mark.
Problem 24-33
Predict the product(s) and write the mechanism for each of the following reactions:
(a)
Bicyclo[4.4.0]decane oriented with C O Cl at top fusion (wedge) and H at bottom fusion (dash) reacts with sodium azide, then water and heat, to form unknown product(s).
(b)
But-3-enoyl chloride reacts with sodium azide, then water and heat to form an unknown product represented by a question mark.
Problem 24-34
The diazotization of aniline first involves the formation of NO+ (nitrosonium ion) by the dehydration of nitrous acid with sulfuric acid. The aniline nitrogen then acts as a nucleophile and eventually loses water. Propose a mechanism for the formation of the dizaonium salt of aniline using curved arrows to show all electron movement.
Problem 24-35

Substituted pyrroles are often prepared by treatment of a 1,4-diketone with ammonia. Propose a mechanism.

A 1,4-diketone reacts with ammonia to form a pyrrole with R and R dash as substituents and water is the second product.
Problem 24-36

3,5-Dimethylisoxazole is prepared by reaction of 2,4-pentanedione with hydroxylamine. Propose a mechanism.

2, 4-Pentanedione reacts with hydroxylamine to produce 3, 5-dimethylisoxazole.
Problem 24-37
One problem with reductive amination as a method of amine synthesis is that by-products are sometimes obtained. For example, reductive amination of benzaldehyde with methylamine leads to a mixture of N-methylbenzylamine and N-methyldibenzylamine. How do you suppose the tertiary amine by-product is formed? Propose a mechanism.
Problem 24-38

Chlorophyll, heme, vitamin B12, and a host of other substances are biosynthesized from porphobilinogen (PBG), which is itself formed from condensation of two molecules of 5-aminolevulinate. The two 5-aminolevulinates are bound to lysine (Lys) amino acids in the enzyme, one in the enamine form and one in the imine form, and their condensation is thought to occur by the following steps. Use curved arrows to show the mechanism of each step.

Two molecules of enzyme-bound 5-aminolevulinate react to produce four intermediates. This further leads to the final product named Porphobilinogen (P B G).
Problem 24-39

Choline, a component of the phospholipids in cell membranes, can be prepared by SN2 reaction of trimethylamine with ethylene oxide. Show the structure of choline, and propose a mechanism for the reaction.

Trimethylamine reacts with ethylene oxide to produce choline, which has an unknown structure.
Problem 24-40

The antitumor antibiotic mitomycin C functions by forming cross-links in DNA chains.

The removal of methanol from mitomycin C forms enamine. This reacts with two amine groups connected to deoxyribonucleic acid to form an intermediate. This reacts to form the final product.
(a)
The first step is loss of methoxide and formation of an iminium ion intermediate that is deprotonated to give an enamine. Show the mechanism.
(b)
The second step is reaction of the enamine with DNA to open the three-membered, nitrogen-containing (aziridine) ring. Show the mechanism.
(c)
The third step is loss of carbamate (NH2CO2) and formation of an unsaturated iminium ion, followed by a conjugate addition of another part of the DNA chain. Show the mechanism.
Problem 24-41

α-Amino acids can be prepared by the Strecker synthesis, a two-step process in which an aldehyde is treated with ammonium cyanide followed by hydrolysis of the amino nitrile intermediate with aqueous acid. Propose a mechanism for the reaction.

Aldehyde R C H O reacts with ammonium cyanide and water forming C with R, H, amino, and cyano substituents. Further reaction with hydronium and heat forms an alpha-amino acid.
Problem 24-42

One of the reactions used in determining the sequence of nucleotides in a strand of DNA is reaction with hydrazine. Propose a mechanism for the following reaction, which occurs by an initial conjugate addition followed by internal amide formation.

A six-membered ring with two incorporated nitrogens, two carbonyls, and two methyl substituents reacts with hydrazine to form an amide.
Problem 24-43

When an α-hydroxy amide is treated with Br2 in aqueous NaOH under Hofmann rearrangement conditions, loss of CO2 occurs and a chain-shortened aldehyde is formed. Propose a mechanism.

2-Hydroxy-2-phenylacetamide reacts with bromine, sodium hydroxide and water to form benzaldehyde, carbon dioxide and ammonia.
Problem 24-44

The following transformation involves a conjugate nucleophilic addition reaction (Section 19.13) followed by an intramolecular nucleophilic acyl substitution reaction (Section 21.2). Show the mechanism.

A carbonyl compound reacts with methylamine to form cyclopentanone with N C H 3 and methoxy group and methanol is the second product.
Problem 24-45

Propose a mechanism for the following reaction:

2-(Benzylamino)ethanol reacts with (Z)-methyl 4-bromobut-2-enoate in the presence of triethylamine and heat to form a product.
Problem 24-46

One step in the biosynthesis of morphine is the reaction of dopamine with p-hydroxyphenylacetaldehyde to give (S)-norcoclaurine. Assuming that the reaction is acid-catalyzed, propose a mechanism.

Dopamine reacts with p-hydroxyphenyl-acetaldehyde to yield (S)-norcoclaurine.

Naming Amines

Problem 24-47
Name the following compounds:
(a)
A benzene ring with an amino substituent. There are two bromine substituents, one ortho and one para to the amino group.
(b)
A cyclopentane ring connected to C H 2 C H 2 N H 2.
(c)
A nitrogen atom with cyclopentyl and ethyl substituents.
(d)
A nitrogen atom with one cyclopentyl and two methyl substituents.
(e)
A five-membered ring incorporating one nitrogen. The nitrogen also has an n-propyl substituent.
(f)
The structure of a four-carbon chain in which one terminal carbon is part of a nitrile. The other terminal carbon has an amino substituent.
Problem 24-48
Draw structures corresponding to the following IUPAC names:
(a)
N,N-Dimethylaniline
(b)
(Cyclohexylmethyl)amine
(c)
N-Methylcyclohexylamine
(d)
(2-Methylcyclohexyl)amine
(e)
3-(N,N-Dimethylamino)propanoic acid
Problem 24-49
Classify each of the amine nitrogen atoms in the following substances as primary, secondary, or tertiary:
(a)
A five-membered ring incorporating one nitrogen. The nitrogen also has a hydrogen.
(b)
An indole with the substituent C H 2 C H 2 N H C H 3 on C 3.
(c)
The structure of lysergic acid diethylamide, a polycyclic compound with several nitrogens.

Amine Basicity

Problem 24-50
Although pyrrole is a much weaker base than most other amines, it is a much stronger acid (pKa ≈ 15 for the pyrrole versus 35 for diethylamine). The N–H hydrogen is readily abstracted by base to yield the pyrrole anion, C4H4N. Explain.
Problem 24-51

Histamine, whose release in the body triggers nasal secretions and constricted airways, has three nitrogen atoms. List them in order of increasing basicity and explain your ordering.

The structure of histamine, a five-membered ring incorporating two nitrogens with a carbon between them. There are two double bonds (one nitrogen has a hydrogen), and an ethylamine substituent.
Problem 24-52
Account for the fact that p-nitroaniline (pKa = 1.0) is less basic than m-nitroaniline (pKa = 2.5) by a factor of 30. Draw resonance structures to support your argument. (The pKa values refer to the corresponding ammonium ions.)

Synthesis of Amines

Problem 24-53
How would you prepare the following substances from 1-butanol?
(a)
Butylamine
(b)
Dibutylamine
(c)
Propylamine
(d)
Pentylamine
(e)
N,N-Dimethylbutylamine
(f)
Propene
Problem 24-54
How would you prepare the following substances from pentanoic acid?
(a)
Pentanamide
(b)
Butylamine
(c)
Pentylamine
(d)
2-Bromopentanoic acid
(e)
Hexanenitrile
(f)
Hexylamine
Problem 24-55
How would you prepare aniline from the following starting materials?
(a)
Benzene
(b)
Benzamide
(c)
Toluene
Problem 24-56
How would you prepare benzylamine, C6H5CH2NH2, from benzene? More than one step is needed.
Problem 24-57
How might you prepare pentylamine from the following starting materials?
(a)
Pentanamide
(b)
Pentanenitrile
(c)
1-Butene
(d)
Hexanamide
(e)
1-Butanol
(f)
5-Decene
(g)
Pentanoic acid
Problem 24-58

How might a reductive amination be used to synthesize ephedrine, an amino alcohol that was widely used for the treatment of bronchial asthma?

The structure of ephedrine. It has benzene ring connected to a C H with hydroxyl linked to another C H with methyl. This is connected to N-H linked to methyl.

Reactions of Amines

Problem 24-59
How would you convert aniline into each of the following products?
(a)
Benzene
(b)
Benzamide
(c)
Toluene
Problem 24-60
Write the structures of the major organic products you would expect from reaction of m-toluidine (m-methylaniline) with the following reagents:
(a)
Br2 (1 equivalent)
(b)
CH3I (excess)
(c)
CH3COCl in pyridine
(d)
The product of (c), then HSO3Cl
Problem 24-61
Show the products from reaction of p-bromoaniline with the following reagents:
(a)
CH3I (excess)
(b)
HCl
(c)
HNO2, H2SO4
(d)
CH3COCl
(e)
CH3MgBr
(f)
CH3CH2Cl, AlCl3
(g)
Product of (c) with CuCl, HCl
(h)
Product of (d) with CH3CH2Cl, AlCl3
Problem 24-62
What are the major products you would expect from Hofmann elimination of the following amines?
(a)
Structure of cyclopentyl methyl amine.
(b)
A nitrogen atom with three substituents: H, benzene ring, and n-hexane (attached by C 2).
(c)
The structure of a six-carbon chain with methyl on C 2 and amine on C 3 position.
Problem 24-63
How would you prepare the following compounds from toluene? A diazonio replacement reaction is needed in some instances.
(a)
The structure of benzene with methyl and amino substituents para to one another.
(b)
The structure of benzene with a methyl substituent and, para to that, a C H 2 N H 2 substituent.
(c)
The structure of benzene with C OO C H 3 on C 1 and iodine on C 3 position.
Problem 24-64
Predict the product(s) of the following reactions. If more than one product is formed, tell which is major.
(a)
Decahydroquinoline reacts with excess methyl iodide to form unknown product A. This reacts with silver oxide and water to form unknown B, that further reacts with heat to form C.
(b)
Benzoyl chloride reacts with sodium azide to form unknown A. This reacts with heat to form unknown B. This reacts with water to form unknown C.
(c)
Isoindoline-1,3-dione reacts with potassium hydroxide to form unknown A. This reacts with (bromomethyl)benzene to form unknown B. This reacts with potassium hydroxide and water to form unknown C.
(d)
1,4-Dibromobutane reacts with one equivalent of methylamine in the presence of sodium hydroxide and water to form an unknown product represented by a question mark.

Spectroscopy

Problem 24-65

Phenacetin, a substance formerly used in over-the-counter headache remedies, has the formula C10H13NO2. Phenacetin is neutral and does not dissolve in either acid or base. When warmed with aqueous NaOH, phenacetin yields an amine, C8H11NO, whose 1H NMR spectrum is shown. When heated with HI, the amine is cleaved to an aminophenol, C6H7NO. What is the structure of phenacetin, and what are the structures of the amine and the aminophenol?

Proton spectrum with signals at shift 1.34 (triplet), 3.40 (wide singlet), 3.93 (quartet), and 6.59 and 6.72 (doublets). Relative areas are 1.50, 1.00, 1.00, 1.00, and 1.00 respectively.
Problem 24-66
Propose structures for amines with the following 1H NMR spectra:
(a)

C3H9NO

Proton spectrum with signals at shift 1.68 (quintet), 2.69 (wide singlet), 2.88 (triplet), and 3.72 (triplet). Relative areas are 1.00, 1.50, 1.00, and 1.00 respectively.
(b)

C4H11NO2

Proton spectrum with signals at shift 1.28 (wide singlet), 2.78 (doublet), 3.39 (singlet), and 4.31 (triplet). Relative areas are 2.00, 2.oo, 6.00, and 1.00 respectively.
(c)

C8H11N

Proton spectrum with signals at shift 1.05 (wide singlet), 2.7 (triplet), 2.95 (triplet), and 7.25 (multiplets). Relative areas are 2.06, 2.02, 2.04, and 4.93 respectively.
Problem 24-67
Draw the structure of the amine that produced the 1H NMR spectrum shown in Problem 24-66(c). This compound has a single strong peak in its IR spectrum at 3280 cm–1.

General Problems

Problem 24-68

Fill in the missing reagents ae in the following scheme:

Acetophenone reacts with a to form 1-phenylethanamine. This reacts with b and c to form styrene. This reacts with d to form 2-phenyloxirane. This reacts with e to form 2-(dimethylamino)-1-phenylethanol.
Problem 24-69

Oxazole is a five-membered aromatic heterocycle. Would you expect oxazole to be more basic or less basic than pyrrole? Explain.

The structure of oxazole, a five membered ring with oxygen and nitrogen atoms separated by one carbon. There are double bonds between the adjacent carbons, and between carbon and nitrogen.
Problem 24-70

Protonation of an amide using strong acid occurs on oxygen rather than on nitrogen. Suggest a reason for this behavior, taking resonance into account.

An amide undergoes a reversible reaction with sulfuric acid to produce a protonated product in which oxygen carries a positive charge.
Problem 24-71

What is the structure of the compound with formula C8H11N that produced the following IR spectrum?

An I R spectrum with major peaks at wavenumbers 1500, 1600, just above and below 3000, and 3400 (single).
Problem 24-72

Fill in the missing reagents ad in the following synthesis of racemic methamphetamine from benzene.

Benzene reacts with a to produce allylbenzene. This reacts with b and c to produce 1-phenylpropan-2-one. This reacts with d to form (R, S)-methamphetamine.
Problem 24-73

Cyclopentamine is an amphetamine-like central nervous system stimulant. Propose a synthesis of cyclopentamine from materials of five carbons or less.

The stucture of cyclopentamine. A nitrogen with H, methyl, and isopropyl substituents. There is also a cyclopentane on C 1 of the isopropyl group.
Problem 24-74

Tetracaine is a substance used as a spinal anesthetic.

The structure of Tetracaine.
(a)
How would you prepare tetracaine from the corresponding aniline derivative, ArNH2?
(b)
How would you prepare tetracaine from p-nitrobenzoic acid?
(c)
How would you prepare tetracaine from benzene?
Problem 24-75

Atropine, C17H23NO3, is a poisonous alkaloid isolated from the leaves and roots of Atropa belladonna, the deadly nightshade. In small doses, atropine acts as a muscle relaxant; 0.5 ng (nanogram, 10–9 g) is sufficient to cause pupil dilation. On basic hydrolysis, atropine yields tropic acid, C6H5CH(CH2OH)CO2H, and tropine, C8H15NO. Tropine is an optically inactive alcohol that yields tropidene on dehydration with H2SO4. Propose a structure for atropine.

The structure of tropidene, a bicyclic compound incorporating a nitrogen with a methyl substituent.
Problem 24-76
Tropidene (Problem 24-75) can be converted by a series of steps into tropilidene (1,3,5-cycloheptatriene). How would you accomplish this conversion?
Problem 24-77

Propose a structure for the product with formula C9H17N that results when 2-(2-cyanoethyl)cyclohexanone is reduced catalytically.

2-(2-Cyanoethyl)cyclohexanone reacts with hydrogen and platinum catalyst to form a product whose chemical formula is C 9 H 1 7 N.
Problem 24-78
Coniine, C8H17N, is the toxic principle of the poison hemlock drunk by Socrates. When subjected to Hofmann elimination, coniine yields 5-(N,N-dimethylamino)-1-octene. If coniine is a secondary amine, what is its structure?
Problem 24-79
How would you synthesize coniine (Problem 24-78) from acrylonitrile (H2C═CHCN) and ethyl 3-oxohexanoate (CH3CH2CH2COCH2CO2Et)? (See Problem 24-77.)
Problem 24-80

Tyramine is an alkaloid found, among other places, in mistletoe and ripe cheese. How would you synthesize tyramine from benzene? From toluene?

The structure of tyramine. A benzene ring with a hydroxyl group on C 1 and two methylene connected to an amine group on C 4.
Problem 24-81
Reaction of anthranilic acid (o-aminobenzoic acid) with HNO2 and H2SO4 yields a diazonium salt that can be treated with base to yield a neutral diazonium carboxylate.
(a)
What is the structure of the neutral diazonium carboxylate?
(b)

Heating the diazonium carboxylate results in the formation of CO2, N2, and an intermediate that reacts with 1,3-cyclopentadiene to yield the following product:

The structure of benzene fused to a six-membered ring. There is a double bond opposite the fusion and a one-carbon bridge between the carbons adjacent to the fusion points.

What is the structure of the intermediate, and what kind of reaction does it undergo with cyclopentadiene?

Problem 24-82

Cyclooctatetraene was first synthesized in 1911 by a route that involved the following transformation:

9-Methyl-9-azabicyclo[3.3.1]non-2-ene is separated from 1,3,5-cyclooctatriene by an arrow.

How might you use the Hofmann elimination to accomplish this reaction? How would you finish the synthesis by converting cyclooctatriene into cyclooctatetraene?

Problem 24-83
Propose structures for compounds that show the following 1H NMR spectra.
(a)

C9H13N

Proton spectrum with signals at shift 2.25 (singlet), 2.89 (singlet), 6.66 (doublet), and 7.03 (doublet). Relative areas are 1.50, 3.00, 1.00, and 1.00 respectively.
(b)

C15H17N

Proton spectrum with signals at shift 1.14 (triplet), 3.40 (quartet), 4.47 (singlet), 6.65 (multiplet) and 7.16 and 7.24 (multiplets). Relative areas are 1.50, 1.00, 1.00, 1.50, 1.50, 2.00 respectively.
Problem 24-84

4-Dimethylaminopyridine (DMAP) acts as a catalyst in acyl transfer reactions. DMAP’s catalytic activity stems from its nucleophilic character at the pyridine nitrogen, not the dimethylamino group. Explain this behavior, taking resonance into account.

The structure of 4-dimethylaminopyridine. It has a pyridine ring linked to a nitrogen connected to two methyl groups.
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