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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

9 • Additional Problems

9 • Additional Problems

Visualizing Chemistry

Problem 9-14
Name the following alkynes, and predict the products of their reaction with (1) H2 in the presence of a Lindlar catalyst and (2) H3O+ in the presence of HgSO4:
(a)
A ball and stick model of a C8 alkyne. Carbon and hydrogen are denoted using gray and white spheres, respectively.
(b)
A ball and stick model of a C10 alkyne. Carbon and hydrogen are denoted using gray and white spheres, respectively.
Problem 9-15
From what alkyne might each of the following substances have been made? (Green = Cl.)
(a)
A ball and stick model of a C6 alkyne. Carbon, oxygen, and hydrogen are denoted using gray, red, and white spheres, respectively.
(b)
A ball and stick model of a substituted cyclohexanxe. Carbon and hydrogen are denoted using gray and white spheres, respectively. Two chlorine groups are denoted using green spheres.
Problem 9-16
How would you prepare the following substances, starting from any compounds having four carbons or fewer?
(a)
A ball and stick model of a cyclopropane that is further linked to a three-carbon chain. Carbon, hydrogen, and oxygen are denoted using gray, white, and red spheres, respectively.
(b)
A ball and stick model of a C6 chain with a double bond and carbonyl.  Carbon, hydrogen, and oxygen are denoted using gray, white, and red spheres, respectively.
Problem 9-17

The following cycloalkyne is too unstable to exist. Explain.

A ball and stick model of a five-membered chain with a triple bond. Carbon and hydrogen are denoted using gray and white spheres, respectively.

Mechanism Problems

Problem 9-18
Assuming that halogens add to alkynes in the same manner as they add to alkenes, propose a mechanism for and predict the product(s) of the reaction of phenylpropyne with Br2.
Problem 9-19
Assuming that strong acids add to alkynes in the same manner as they add to alkenes, propose a mechanism for each of the following reactions.
(a)
A C5 terminal alkyne reacts with two moles of hydrogen chloride to form 2,2-dichloropentane.
(b)
A C4 internal alkyne reacts with two moles of hydrogen bromide to form 2,2-dibromobutane.
(c)
A phenyl alkyne reacts with two moles of hydrogen chloride to form a benzene ring with a carbon connected to a  dichloroethyl group
Problem 9-20
The mercury-catalyzed hydration of alkynes involves the formation of an organomercury enol intermediate. Draw the electron-pushing mechanism to show how each of the following intermediates is formed.
(a)
A phenyl alkyne reacts with water, sulfuric acid, and mercuric sulfate to form a benzene ring connected to an ionic organomercury enol sulfate intermediate.
(b)
A C3 alkyne reacts with water, sulfuric acid, and mercuric sulfate to form a C3 ionic organomercury enol sulfate  intermediate.
(c)
A C4 terminal alkyne reacts with water, sulfuric acid, and mercuric sulfate to form a C4 ionic organomercury enol sulfate  intermediate.
Problem 9-21
The final step in the hydration of an alkyne under acidic conditions is the tautomerization of an enol intermediate to give the corresponding ketone. The mechanism involves a protonation followed by a deprotonation. Show the mechanism for each of the following tautomerizations.
(a)
A benzene ring connected to an OH-substituted alkene reacts with hydronium ions to form a benzene ring with a C O C H 3 group.
(b)
A C3 OH-substituted alkene reacts with hydronium ions  to form acetone.
(c)
A  C5  OH-substituted alkene reacts with hydronium ion to form a C5 methyl ketone.
Problem 9-22
Predict the product(s) and show the complete electron-pushing mechanism for each of the following dissolving metal reductions.
(a)
The figure shows a C5 terminal alkyne reacting with lithium and ammonia.
(b)
The figure shows a C5  terminal alkyne reacting with lithium and deuterated ammonia.
(c)
The figure shows a phenyl-substituted C3 internal alkyne reacting with lithium and deuterated ammonia.
Problem 9-23
Identify the mechanisms for the following reactions as polar, radical, or both.
(a)
A C6 internal alkyne reacts with lithium and ammonia to form a trans alkene.
(b)
A C6 internal alkyne reacts with bromine to form a trans dibromoalkene
(c)
A C6 internal alkyne reacts with two moles of hydrogen bromide to form a dibromo substituted alkane
Problem 9-24
Predict the product and provide the complete electron-pushing mechanism for the following two-step synthetic processes.
(a)
A benzene ring connected to a C2 alkyne reacts with sodium amide and methyl iodide.
(b)
A C5 keto substituted alkyne reacts with sodium amide and ethyl iodide.
(c)
A C4 terminal alkyne reacts with sodium amide and phenyl methyl bromide.
Problem 9-25

Reaction of acetone with D3O+ yields hexadeuterioacetone. That is, all the hydrogens in acetone are exchanged for deuterium. Review the mechanism of mercuric-ion-catalyzed alkyne hydration, and then propose a mechanism for this deuterium incorporation.

The figure shows the reaction of acetone with tri-deuterium oxide to form hexadeuterioacetone.

Naming Alkynes

Problem 9-26
Give IUPAC names for the following compounds:
(a)
A C8 internal alkyne with two methyl groups at C2 and a triple bond at C3.
(b)
A C8 dialkyne with triple bonds at C2 and C5 positions.
(c)
A C9 enyne with a  triple bond at C3, double bond at C5 , and two methyl groups at C2 and C5.
(d)
A C8 dialkyne with triple bonds at C1 , C5, and two methyl groups at C4.
(e)
A C6 dienyne with a triple bond at C2 and two double bonds at C3 and C5.
(f)
A C13 alkyne with a methyl group at C2,  a triple bond at C4, and two ethyl groups at C3 and C6.
Problem 9-27
Draw structures corresponding to the following names:
(a)
3,3-Dimethyl-4-octyne
(b)
3-Ethyl-5-methyl-1,6,8-decatriyne
(c)
2,2,5,5-Tetramethyl-3-hexyne
(d)
3,4-Dimethylcyclodecyne
(e)
3,5-Heptadien-1-yne
(f)
3-Chloro-4,4-dimethyl-1-nonen-6-yne
(g)
3-sec-Butyl-1-heptyne
(h)
5-tert-Butyl-2-methyl-3-octyne
Problem 9-28
The following two hydrocarbons have been isolated from various plants in the sunflower family. Name them according to IUPAC rules.
(a)
CH3CH = CHC CC CCH = CHCH = CHCH = CH2 (all trans)
(b)
CH3C CC CC CC CC CCH = CH2

Reactions of Alkynes

Problem 9-29

Terminal alkynes react with Br2 and water to yield bromo ketones. For example:

A phenyl alkyne reacts with bromine and water to form a phenyl bromo methyl ketone.

Propose a mechanism for the reaction. To what reaction of alkenes is the process analogous?

Problem 9-30

Predict the products of the following reactions:

A terminal enyne reacts with hydrogen and palladium catalyst to form an unknown product A. The reactant also reacts with hydrogen and Lindlar catalyst to form an unknown product B.
Problem 9-31
Predict the products from reaction of 1-hexyne with the following reagents:
(a)
1 equiv HBr
(b)
1 equiv Cl2
(c)
H2, Lindlar catalyst
(d)
NaNH2 in NH3, then CH3Br
(e)
H2O, H2SO4, HgSO4
(f)
2 equiv HCl
Problem 9-32
Predict the products from reaction of 5-decyne with the following reagents:
(a)
H2, Lindlar catalyst
(b)
Li in NH3
(c)
1 equiv Br2
(d)
BH3 in THF, then H2O2, OH
(e)
H2O, H2SO4, HgSO4
(f)
Excess H2, Pd/C catalyst
Problem 9-33
Predict the products from reaction of 2-hexyne with the following reagents:
(a)
2 equiv Br2
(b)
1 equiv HBr
(c)
Excess HBr
(d)
Li in NH3
(e)
H2O, H2SO4, HgSO4
Problem 9-34
Propose structures for hydrocarbons that give the following products on oxidative cleavage by KMnO4 or O3:
(a)
The figure shows carbon dioxide and heptanoic acid, the products of oxidative cleavage.
(b)
The figure shows acetic acid and benzoic acid, the products of oxidative cleavage.
(c)
C10 dicarboxylic acid with carboxylate groups at C1 and C10.
(d)
Acetal aldehyde, a C5  carboxylic acid with a C2 carbonyl, and carbon dioxide, the products of oxidative cleavage.
(e)
C7 carboxylic acid with carbonyl at C2, aldehyde at C7, and carbon dioxide, the products of oxidative cleavage.
Problem 9-35

Identify the reagents a–c in the following scheme:

A C5 terminal alkyne reacts with reagent  a to add an ethyl group at C1, forming a cis alkene via reagent b and a substituted cyclopropane ring  with reagent c.

Organic Synthesis

Problem 9-36

How would you carry out the following multistep conversions? More than one step may be needed in some instances.

Figure shows eight reactions of a terminal alkyne. Each arrow points in different directions to give either an aldehyde, alkane, alkene, epoxide, ketone, alkyne, alcohol, or an alkyl halide.
Problem 9-37
How would you carry out the following reactions?
(a)
A C4 alkyne chain reacts in the presence of an unknown reagent represented as a question mark to form  methyl ethyl ketone.
(b)
A C4 alkyne chain reacts in the presence of an unknown reagent represented as a question mark to form butyraldehyde
(c)
A phenyl alkyne reacts with an unknown reagent represented as a question mark forming a phenyl alkyne with a terminal methyl group.
(d)
A phenyl alkyne reacts with an unknown reagent represented as a question mark forming a cis-phenyl alkene with a terminal methyl group.
(e)
1-Butyne reacts in the presence of an unknown reagent represented as a question mark to form propionic acid
(f)
A C6 alkene reacts in the presence of an unknown reagent indicated as a question mark via two steps to form 1-hexyne.
Problem 9-38
Each of the following syntheses requires more than one step. How would you carry them out?
(a)
Figure shows pentyne reacting  in the presence of an unknown reagent indicated as a question mark to form butanal.
(b)
A C6 alkyne reacts in the presence of an unknown reagent indicated as a question mark to form an alkene.
Problem 9-39

How would you carry out the following multistep transformation?

1-Hexyne reacts in the presence of an unknown reagent indicated by a question mark to form a C8 compound having a cyclopropane ring.
Problem 9-40

How would you carry out the following multistep conversions?

Styrene reacts in the presence of an unknown reagent indicated by a question mark to form 2-phenyl acetaldehyde. Styrene reacts in the presence of an unknown reagent indicated by a question mark to form prop-1-en-1ylbenzene.
Problem 9-41
Synthesize the following compounds using 1-butyne as the only source of carbon, along with any inorganic reagents you need. More than one step may be needed.
(a)
1,1,2,2-Tetrachlorobutane
(b)
1,1-Dichloro-2-ethylcyclopropane
Problem 9-42
How would you synthesize the following compounds from acetylene and any alkyl halides with four or fewer carbons? More than one step may be needed.
(a)
The structure of 1-pentyne.
(b)
The structure of hex-3-yne.
(c)
The structure of 4-methylpent-1-ene.
(d)
The figure shows an C8 carbon chain with a carbonyl group at C4.
(e)
The figure shows a C6 carbon chain with an aldehyde group.
Problem 9-43
How would you carry out the following reactions to introduce deuterium into organic molecules?
(a)
A C6 alkyne reacts in the presence of an unknown reagent denoted as a question mark to form a cis-deuterated alkene.
(b)
A C6 alkyne reacts in the presence of an unknown reagent denoted as a question mark to form a trans-deuterated alkene.
(c)
Pentyne reacts with an unknown reagent denoted as a question mark to form a deuterium-substituted alkyne.
(d)
Ethynylbenzene reacts with an unknown reagent indicated as a question mark to form a deuterium-substituted alkene.
Problem 9-44
How would you prepare cyclodecyne starting from acetylene and any required alkyl halide?
Problem 9-45

The sex attractant given off by the common housefly is an alkene named muscalure. Propose a synthesis of muscalure starting from acetylene and any alkyl halides needed. What is the IUPAC name for muscalure?

The structure of muscalure.

General Problems

Problem 9-46
A hydrocarbon of unknown structure has the formula C8H10. On catalytic hydrogenation over the Lindlar catalyst, 1 equivalent of H2 is absorbed. On hydrogenation over a palladium catalyst, 3 equivalents of H2 are absorbed.
(a)
How many degrees of unsaturation are present in the unknown structure?
(b)
How many triple bonds are present?
(c)
How many double bonds are present?
(d)
How many rings are present?
(e)
Draw a structure that fits the data.
Problem 9-47
Compound A (C9H12) absorbed 3 equivalents of H2 on catalytic reduction over a palladium catalyst to give B (C9H18). On ozonolysis, compound A gave, among other things, a ketone that was identified as cyclohexanone. On treatment with NaNH2 in NH3, followed by addition of iodomethane, compound A gave a new hydrocarbon, C (C10H14). What are the structures of A, B, and C?
Problem 9-48
Hydrocarbon A has the formula C12H8. It absorbs 8 equivalents of H2 on catalytic reduction over a palladium catalyst. On ozonolysis, only two products are formed: oxalic acid (HO2CCO2H) and succinic acid (HO2CCH2CH2CO2H). Write the reactions, and propose a structure for A.
Problem 9-49
Occasionally, a chemist might need to invert the stereochemistry of an alkene—that is, to convert a cis alkene to a trans alkene, or vice versa. There is no one-step method for doing an alkene inversion, but the transformation can be carried out by combining several reactions in the proper sequence. How would you carry out the following reactions?
(a)
trans-5-Decene reacting in the presence of an unknown reagent indicated as a question mark to form cis-5-decene.
(b)
cis-5-Decene reacting in the presence of an unknown reagent indicated as a question mark to form trans-5-decene.
Problem 9-50

Organometallic reagents such as sodium acetylide undergo an addition reaction with ketones, giving alcohols:

Acetone reacts in the presence of sodium acetylide and hydronium ion to form an alcohol.

How might you use this reaction to prepare 2-methyl-1,3-butadiene, the starting material used in the manufacture of synthetic rubber?

Problem 9-51

The oral contraceptive agent Mestranol is synthesized using a carbonyl addition reaction like that shown in Problem 9-50. Draw the structure of the ketone needed.

The structure of mestranol.
Problem 9-52

1-Octen-3-ol, a potent mosquito attractant commonly used in mosquito traps, can be prepared in two steps from hexanal, CH3CH2CH2CH2CH2CHO. The first step is an acetylide-addition reaction like that described in Problem 9-50. What is the structure of the product from the first step, and how can it be converted into 1-octen-3-ol?

The structure of 1-octen-3-ol.
Problem 9-53
Erythrogenic acid, C18H26O2, is an acetylenic fatty acid that turns a vivid red on exposure to light. On catalytic hydrogenation over a palladium catalyst, 5 equivalents of H2 are absorbed, and stearic acid, CH3(CH2)16CO2H, is produced. Ozonolysis of erythrogenic acid gives four products: formaldehyde, CH2O; oxalic acid, HO2CCO2H; azelaic acid, HO2C(CH2)7CO2H; and the aldehyde acid OHC(CH2)4CO2H. Draw two possible structures for erythrogenic acid, and suggest a way to tell them apart by carrying out some simple reactions.
Problem 9-54

Hydrocarbon A has the formula C9H12 and absorbs 3 equivalents of H2 to yield B, C9H18, when hydrogenated over a Pd/C catalyst. On treatment of A with aqueous H2SO4 in the presence of mercury(II), two isomeric ketones, C and D, are produced. Oxidation of A with KMnO4 gives a mixture of acetic acid (CH3CO2H) and the tricarboxylic acid E. Propose structures for compounds AD, and write the reactions.

The structure of a C7 tricarboxylic acid labeled E.
Problem 9-55

A cumulene is a compound with three adjacent double bonds. Draw an orbital picture of a cumulene. What kind of hybridization do the two central carbon atoms have? What is the geometric relationship of the substituents on one end to the substituents on the other end? What kind of isomerism is possible? Make a model to help see the answer.

The structure of a cumulene.
Problem 9-56

Which of the following bases could be used to deprotonate 1-butyne?

(a)The structure of potassium hydroxide.(b)The structure of the sodium salt of the methylene anion connected to a sulfonyl group that is further connected to a methyl group.(c)The structure of butyllithium.(d)The structure of the sodium salt of the methylene anion  of acetone.

Problem 9-57
Arrange the following carbocations in order of increasing stability.
(a)
The structure of three cyclopentene carbocations with positive charges at C 4, C 1, and C 3.
(b)
The structure of three 1-pentene carbocations, with positive charges at C 3, C 2, and C 4.
(c)
The structure of three 4-methylcyclohexene carbocations with positive charges at C 1, C 4, and C 5.
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