Carbonyls and Alcohols

Question 1

Reduction and Conversion of Carboxylic Acids to:

Acid Halides

Esters

Primary Alcohols

Acid Anhydride

Answer 1

• Acid halide
  
  • SOCl₂
• Esters
  
  • R’OH/H⁺
• Primary alcohols
  
  • LiAlH₄
  • NH₄Cl
• Acid anhydride
  
  • Heat

Question 2

Transesterification

Answer 2

• At high temps, esters can exchange their alkoxy group in the presence of acid and an alcohol

Question 3

Acid Halide Reactivity

Answer 3

• The most reactive of carbonyl centers; halides are great leaving groups

Question 4

Oxidation and Oxidizing Agents

Answer 4

• Adds more oxygens
• PCC
  
  • Weaker oxidizer
• K₂Cr₂O₇
  
  • _​Strong
• KMnO₄
  
  • Strong
• For something to be oxidized, it must have hydrogens to lose
• Oxidizing agents have lots of oxygens!

Question 5

Reduction and Reducing Agents

Answer 5

• Adding more hydrogens
• LiAlH₄/NH₄Cl
  
  • More reactive than NaBH₄
  • Will reduce every carbonyl center
• NaBH₄/NH₄Cl
  
  • Only reduces ketons and aldehydes
• Whatever is being reduced must have oxygens to lose
• Reducing agents have lots of hydrogens!

Question 6

Grignard Reaction

Answer 6

• Always generates a hydroxyl group where the carbonyl oxygen was

Question 7

Aldol Condensation

Answer 7

• Removal of alpha proton from ketone/aldehyde
• Then reacts on itself
• Called a Claisen when with esters

Question 8

Wittig Reaction

Answer 8

• Converts a carbonyl into an alkene, with stereoselectivity

Question 9

Pinacol Rearrangement

Answer 9

• Converts a vicinal diol into a ketone
  
  • Alkyl rearrangment, converting a tertiary carbocation into a resonance stabilized carbocation

Question 10

Iodoform Reaction

Answer 10

• Tests for the presence of methyl ketones
• Forms carboxylic acid and a haloform (

Question 11

Wölff-Kishner Reduction

Answer 11

• Converts a ketone or aldehyde into an alkane
• Uses basic conditions and a hydrazine, followed by a hydroxide workup