John McMurry, Professor Emeritus

Problem 21-1

(a)

4-Methylpentanoyl chloride

(b)

Cyclohexylacetamide

(c)

Isopropyl 2-methylpropanoate

(d)

Benzoic anhydride

(e)

Isopropyl cyclopentanecarboxylate

(f)

Cyclopentyl 2-methylpropanoate

(g)

N-Methyl-4-pentenamide

(h)

(R)-2-Hydroxypropanoyl phosphate

(i)

Ethyl 2,3-dimethyl-2-butenethioate

Problem 21-2

(a)

(b)

(c)

(d)

The structure of methyl 1-methylcyclohexanecarboxylate shows a methyl ester and methyl group both attached to the same carbon of a cyclohexane ring.

(e)

The structure of ethyl 3-oxopentanoate shows a five-carbon chain, C 1 and C 3 of which are carbonyl groups. Alttached to the carbonyl group at C 1 is an ethoxy group.

(f)

The structure of methyl-p-bromobenzenethioate shows a carbonyl group to which is attached a methyl sylfide group and a benzene ring with a bromine atom in the 4-position.

(g)

The structure of formic propanoic anhydride shows two carbonyl groups linked by an oxygen atom. A hydrogen atom is attached to one of the carbonyls and an ethyl group to the other.

(h)

The structure of cis-2-methylcyclopentanecarbonyl bromide shows a cyclopentane ring with a methyl group drawn as a wedge on one carbon and a carbonyl group on the next carbon of the ring, drawn as a wedge. Also attached to the carbonyl group is a bromine atom.

Problem 21-3

Methoxide ion adds to the carbonyl carbon of benzoyl chloride, forming an intermediate, which on elimination of a chloride ion, gives the product methyl benzoate.

Problem 21-4

(a)

Acetyl chloride > Methyl acetate > Acetamide

(b)

Hexafluoroisopropyl acetate > 2,2,2-Trichloroethyl acetate > Ethyl acetate

Problem 21-5

(a)

CH₃CO₂^– Na⁺

(b)

CH₃CONH₂

(c)

CH₃CO₂CH₃ + CH₃CO₂^– Na⁺

(d)

CH₃CONHCH₃

Problem 21-6

Methyl-2-cyclopentylacetate reacts with hydroxide ions. The product is not shown. The carboxylate analog of methyl-2-cyclopentylacetate reacts with methoxide ions and again the product is not shown.

Problem 21-7

(a)

Acetic acid + 1-butanol

(b)

Butanoic acid + methanol

(c)

Cyclopentanecarboxylic acid + isopropyl alcohol

Problem 21-8

The lactone structure comprises of a six-membered ring containing a carbonyl group with an oxygen atom next to it in the ring.

Problem 21-9

(a)

Propanoyl chloride + methanol

(b)

Acetyl chloride + ethanol

(c)

Benzoyl chloride + ethanol

Problem 21-10

Benzoyl chloride + cyclohexanol

Problem 21-11

This is a typical nucleophilic acyl substitution reaction, with morpholine as the nucleophile and chloride as the leaving group.

Problem 21-12

(a)

Propanoyl chloride + methylamine

(b)

Benzoyl chloride + diethylamine

(c)

Propanoyl chloride + ammonia

Problem 21-13

(a)

Benzoyl chloride + [(CH₃)₂CH]₂CuLi, or 2-methylpropanoyl chloride + Ph₂CuLi

(b)

2-Propenoyl chloride + (CH₃CH₂CH₂)₂CuLi, or butanoyl chloride + (H₂C

\text{=}

CH)₂CuLi

Problem 21-14

This is a typical nucleophilic acyl substitution reaction, with p-hydroxyaniline as the nucleophile and acetate ion as the leaving group.

Problem 21-15

Monomethyl ester of benzene-1,2-dicarboxylic acid

Problem 21-16

Reaction of a carboxylic acid with an alkoxide ion gives the carboxylate ion.

Problem 21-17

LiAlH₄ gives HOCH₂CH₂CH₂CH₂OH; DIBAH gives HOCH₂CH₂CH₂CHO.

Problem 21-18

(a)

CH₃CH₂CH₂CH(CH₃)CH₂OH + CH₃OH

(b)

PhOH + PhCH₂OH

Problem 21-19

(a)

Ethyl benzoate + 2 CH₃MgBr

(b)

Ethyl acetate + 2 PhMgBr

(c)

Ethyl pentanoate + 2 CH₃CH₂MgBr

Problem 21-20

(a)

H₂O, NaOH

(b)

Benzoic acid + LiAlH₄

(c)

LiAlH₄

Problem 21-21

1. Mg; 2. CO₂, then H₃O⁺; 3. SOCl₂; 4. (CH₃)₂NH; 5. LiAlH₄

Problem 21-22

The reaction shows the mechanism for the reaction of an ester attached to adenosine and a thiol forming acetyl coenzyme A, and a product in which a phosphate group is bonded to adenosine.

Problem 21-23

(a)

(b)

The structure shows a repeating unit of O C H 2 C H 2 O C O (C H 2) 6 C O with subscript n.

(c)

The repeating unit of a polymer in brackets with N H bonded to six methylene bonded to N H bonded to a carbonyl group which itself is bonded to four methylene units and then another carbonyl group.

Problem 21-24

The structure shows a repeating unit of N H (C H 2) 6 N H C O (C H 2) 4 C O in parentheses with subscript n.

Problem 21-25

(a)

Ester

(b)

Acid chloride

(c)

Carboxylic acid

(d)

Aliphatic ketone or cyclohexanone

Problem 21-26

(a)

CH₃CH₂CH₂CO₂CH₂CH₃ and other possibilities

(b)

CH₃CON(CH₃)₂

(c)

CH₃CH

\text{=}

CHCOCl or H₂C

\text{=}

C(CH₃)COCl

Chapter 21