John McMurry, Professor Emeritus

Problem 7-1

(a)

1

(b)

2

(c)

2

Problem 7-2

(a)

5

(b)

5

(c)

3

(d)

1

(e)

6

(f)

5

Problem 7-3

C₁₆H₁₃ClN₂O

Problem 7-4

(a)

3,4,4-Trimethyl-1-pentene

(b)

3-Methyl-3-hexene

(c)

4,7-Dimethyl-2,5-octadiene

(d)

6-Ethyl-7-methyl-4-nonene

Problem 7-5

(a)

A condensed structural formula has a 6-carbon chain with double bonds between C1-C2 and C5-C6. C2 is bonded to a methyl group.

(b)

A condensed structural formula has a 7-carbon chain with a double bond between C3-C4. C1 and C3 are bonded to three methyl and one ethyl group, respectively.

(c)

A structure of octane with double bonds between C1-C2, C4-C5, and C6-C7. C2 and C3 are bonded to one methyl and two methyl groups, respectively.

(d)

A 2-carbon chain with a double bond in between. C1 and C2 are each bonded to two isopropyl groups.

Problem 7-6

(a)

1,2-Dimethylcyclohexene

(b)

4,4-Dimethylcycloheptene

(c)

3-Isopropylcyclopentene

Problem 7-7

(a)

2,5,5-Trimethylhex-2-ene

(b)

2,3-Dimethylcyclohexa-1,3-diene

Problem 7-8

A structure of a 23-carbon chain. C9 is cis double bonded to C10.

Problem 7-9

Compounds (c), (e), and (f) have cis–trans isomers.

Problem 7-10

(a)

cis-4,5-Dimethyl-2-hexene

(b)

trans-6-Methyl-3-heptene

Problem 7-11

(a)

−CH₃

(b)

−Cl

(c)

−CH

\text{=}

CH₂

(d)

−OCH₃

(e)

−CH

\text{=}

O

(f)

−CH

\text{=}

O

Problem 7-12

(a)

−Cl, −OH, −CH₃, −H

(b)

−CH₂OH, −CH

\text{=}

CH₂, −CH₂CH₃, −CH₃

(c)

−CO₂H, −CH₂OH, −C

\text{≡}

N, −CH₂NH₂

(d)

−CH₂OCH₃, −C

\text{≡}

N, −C

\text{≡}

CH, −CH₂CH₃

Problem 7-13

(a)

Z

(b)

E

(c)

Z

(d)

E

Problem 7-14

A double bond with vinyl (up) and isopropyl (down) on the left and C O O C H 3 (up) and hydroxymethyl (down) on the right. Text reads Z.

Problem 7-15

(a)

2-Methylpropene is more stable than 1-butene.

(b)

trans-2-Hexene is more stable than cis-2-hexene.

(c)

1-Methylcyclohexene is more stable than 3-methylcyclohexene.

Problem 7-16

(a)

Chlorocyclohexane

(b)

2-Bromo-2-methylpentane

(c)

4-Methyl-2-pentanol

(d)

1-Bromo-1-methylcyclohexane

Problem 7-17

(a)

Cyclopentene

(b)

1-Ethylcyclohexene or ethylidenecyclohexane

(c)

3-Hexene

(d)

Vinylcyclohexane (cyclohexylethylene)

Problem 7-18

(a)

2,4-dimethyl-3-hexene with a cation on C 4

(b)

Problem 7-19

In the conformation shown, only the methyl- group C−H that is parallel to the carbocation p orbital can show hyperconjugation.

Problem 7-20

The second step is exergonic; the transition state resembles the carbocation.

Problem 7-21

A reaction mechanism shows vinylcyclohexane reacting with hydrogen bromide to form 1-bromo-1-ethylcyclohexane via secondary carbocation and hydride shift to tertiary carbocation.

Chapter 7