Carbonyl Chemistry
Identify the functional group:
O
║
R — C — R′
Ketone
A ketone contains a carbonyl (C=O) with a carbon group attached to both sides of the carbonyl carbon. This is part of the aldehyde/ketone section of your carbonyl notes
Identify this functional group:
O
║
R — C — OH
Carboxylic acid
What is the name of the intermediate formed after a nucleophile attacks the carbonyl carbon during nucleophilic acyl substitution?
Structure:
O⁻
|
Nu — C — LG
|
R
Tetrahedral intermediate
This is the intermediate used in the nucleophilic acyl substitution mechanisms in your notes.
What reagent would you use to make this transformation?
CH₃CH₂—Br → CH₃CH₂—C≡N
CN⁻
For example: NaCN
Draw the major organic product:
CH₃CH₂CHO
NaBH₄
↓
?
1-Propanol CH₃—CH₂—CH₂—OH
What type of product forms when an aldehyde or ketone reacts with a primary amine (R–NH₂)?
O NR′
║ ║
R — C — R′ + H₂N—R″ → R—C—R′
Identify this carboxylic acid derivative:
O
║
R — C — O — R′
Ester
Esters are one of the carboxylic-acid derivatives covered in your notes, with the general structure R–C(=O)–O–R′.
In a nucleophilic acyl substitution, what happens immediately after the tetrahedral intermediate forms?
Choose the correct answer:
A. A carbocation forms
B. The carbonyl reforms and the leaving group leaves
C. The carbonyl carbon is reduced
D. The nucleophile leaves
B. The carbonyl reforms and the leaving group leaves
This follows the nucleophilic acyl substitution mechanism in your notes.
What type of product is formed when a nitrile is reduced?
R—C≡N → ?
A primary amine
R—C≡N → R—CH₂—NH₂
Draw the major organic product:
CH₃CH₂CH₂Br + NaCN → ?
CH₃CH₂CH₂C≡N
Butanenitrile
Complete the reaction and identify the product type:
Acetone + a secondary amine → ?
What type of carbonyl-derived product forms?
Enamine
Starting ketone:
O
║
CH₃ — C — CH₃
↓ secondary amine
Enamine:
CH₂ = C — CH₃
|
NR₂
Rank these carboxylic acid derivatives from MOST reactive to LEAST reactive toward nucleophilic acyl substitution:
Acid chloride Ester Amide
O O O
║ ║ ║
R — C — Cl R — C — OR′ R — C — NR′₂
Acid chloride > Ester > Amide
This is based on the carboxylic-acid derivative stability/reactivity material in your notes.
In a Baeyer–Villiger oxidation, what functional group does a ketone become?
O
║
R — C — R′ + peroxyacid → ?
An ester
Overall transformation:
O O
║ ║
R — C — R′ → R — C — O — R′
What type of organometallic reagent is this?
R₂CuLi
And what is it called?
Gilman reagent — an organocuprate
General structure:
R₂CuLi
Draw the major product:
An unsymmetrical epoxide is treated with:
1. NaOCH₃
2. H₂O
Which carbon gets the –OCH₃ group?
–OCH₃ goes on the LESS substituted carbon.
General product:
BEFORE AFTER
O OH
/ \ |
C*---CH₂ → C*—CH₂—OCH₃
↑ ↑
less substituted OCH₃ attacks here
Rank these carbonyl compounds from MOST reactive to LEAST reactive toward nucleophilic addition:
Formaldehyde — Acetaldehyde — Acetone
Structures:
Formaldehyde Acetaldehyde Acetone
O O O
║ ║ ║
H — C — H CH₃—C—H CH₃—C—CH₃
Formaldehyde > Acetaldehyde > Acetone
Your notes specifically cover the relative reactivity of aldehydes and ketones toward nucleophilic addition.
Draw the major organic product:
O
║
CH₃ — C — Cl + CH₃OH
O
║
CH₃ — C — O — CH₃
Methyl acetate + HCl
During a Baeyer–Villiger oxidation, one of the groups attached to the carbonyl carbon migrates.
Which generally has the greater migratory aptitude:
tertiary alkyl or methyl?
Tertiary alkyl
The group with the greater migratory aptitude preferentially migrates during the rearrangement.
Choose the reagents needed for this synthesis:
CH₃CH₂—Br → CH₃CH₂CH₂—NH₂
You need to turn a 2-carbon alkyl bromide into a 3-carbon primary amine.
Step 1: NaCN
Step 2: Reduce the nitrile
The synthesis is:
CH₃CH₂—Br
│
NaCN
↓
CH₃CH₂—C≡N
│
reduction
↓
CH₃CH₂—CH₂—NH₂
Draw the major organic product:
O
║
CH₃ — C — Cl + NH₃
What functional group is formed?
Acetamide (ethanamide)
O
║
CH₃ — C — NH₂
Complete the reaction and draw the major organic product:
O
║
CH₃ — C — CH₃ + CH₃NH₂
H⁺
↓
?
N—CH₃
║
CH₃ — C — CH₃
Draw the major organic product and identify the reaction:
O
║
CH₃ — C — OH + HO—CH₂CH₃
H⁺, heat
↓
?
O
║
CH₃ — C — O — CH₂CH₃
Ethyl acetate + H₂O
Draw the major product of this Baeyer–Villiger oxidation:
O
║
CH₃ — C — C(CH₃)₃
peroxyacid
↓
?
The tert-butyl group migrates, producing:
O
║
CH₃ — C — O — C(CH₃)₃
Choose the reagents needed to complete this synthesis:
CH₃CH₂OH → CH₃CH(OH)CH₃
Step 1 — Oxidize ethanol to acetaldehyde
CH₃CH₂OH → CH₃CHO
Use Swern oxidation.
Step 2 — Add a carbon with a Grignard
CH₃CHO
1. CH₃MgBr
2. H₃O⁺
↓
CH₃CH(OH)CH₃
Complete this synthesis. Give the reagents for each step and draw the intermediate.
CH₃CH₂Br ─────────→ CH₃CH₂CH₂NH₂
You must increase the carbon chain by ONE carbon.
Step 1: NaCN
Step 2: Reduce the nitrile
CH₃CH₂—Br
│
│ NaCN
↓
CH₃CH₂—C≡N
│
│ reduction
↓
CH₃CH₂—CH₂—NH₂