Substitution and Elimination Reactions

Question 1

weak base: tertiary alkyl halide

Answer 1

Sn1 is favored UNLESS there is a bulky base, then E1 is favored

Question 2

weak base: primary alkyl halide

Answer 2

no Sn1/E1 reactions, because primary carbocations are too unstable

Question 3

strong base: primary alkyl halide

Answer 3

Sn2 is favored, unless there is a bulky base, then E2 is favored

Question 4

strong base: secondary alkyl halide

Answer 4

If weak nucleophile, it does Sn2

if strong nucleophile, it does E2

Question 5

strong base: tertiary alkyl halide

Answer 5

E2

Question 6

substitution: reagent functions as…

Answer 6

nucleophile

Question 7

elimination: reagent functions as…

Answer 7

base

Question 8

solvents: Sn2

Answer 8

polar aprotic

Question 9

solvents: Sn1

Answer 9

polar protic

Question 10

X and H must be anti-peri planar for ___ reactions

Answer 10

E2

Question 11

E1 vs. E2:

Zaitsev vs Hoffman

Answer 11

E1: always Zaitsev product

E2: Zaitsev or Hoffman (if there is a bulky base)

Question 12

which nucleophile is strongest in an aprotic reagent?

Answer 12

F- is better than I-

Question 13

which nucleophile is strongest in a protic reagent?

Answer 13

I- is better than F-

Question 14

Sn2: products

Answer 14

only inverted products are formed

Question 15

E2 products

Answer 15

both E and Z (more E) unless the beta-carbon only has one H, then one isomer is formed

Question 16

Sn1 products

Answer 16

racemic mixture, slightly more inverted product

Question 17

E1 products

Answer 17

both E and Z are formed, with more E

Question 18

name 3 polar APROTIC solvents

Answer 18

acetonitrile

DMF

DMSO