Chem 212 Alkyl Halide Problems 4

Provide the products of the following reactions. Be sure to show all appropriate stereochemistry. Show the mechanism for all the problems.

Chem 212 Alkyl halide problems 4

7.

NaCN Br

1.

CN

KOH TsO H

acetone

NaN3

8. NaI

Br

2.

TsO H

I

DMSO

N3

DMF

H Br KOH

3.

Br

4.

Br

OH

NaN3

9.

I

H Br

N3

acetone

NaOH

NaI

10.

H2O

NaCN

5.

H Br

acetone TsO H

CN

NaOMe

11.

MeOH

acetone

TsO H

N3

H Br

NaI

6.

I

NaN3

12.

DMF

For the following pairs of reactions predict which will be faster and explain why.

13. a)

Cl

NaN3 EtOH

b)

I

NaN3

14. a)

Br

H 2O

Br

N3

EtOH

OH

heat b)

Br H

15. a)

H2O heat

Br

NaSH

NaCN

16. a)

N3

faster better leaving group

faster tertiary carbocation more stable

MeOH

Br

DMF

17. a)

18. a)

b)

Br

NaSH

faster, both are in a poor SN2 solvent, but hydroxide is better nucleophile

OH

H2O

O O

NaCN Br

faster primary over SH secondary

H2O NaO2CCH3

Br

SH

CN

NaOH Br

H

faster polar, aprotic solvent

NaCN

b)

b)

OH

CN

DMF

CN

NaCN

b) Br

DMF

CN

faster primary over secondary