test 3-reaction mechanisms

Question 1

what makes a good leaving group?

Answer 1

a weak base/the conjugate of the strong acid.

Question 2

what are some strong and bulky bases?

Answer 2

t-BuOk, KOtBu

Question 3

what are some strong and small bases?

Answer 3

NaOET
MCPBr
NaOH
NaOMe

Question 4

what are some small weak bases?

Answer 4

MeOH, EtOH

Question 5

how do you know when enantiomers will be in the products of a reaction?

Answer 5

if a new chiral center is formed

Question 6

how do you know when mark or anti-mark addition occurs?

Answer 6

anti-mark addition occurs in the presence of peroxides

Question 7

why cant large bases do Sn2?

Answer 7

the base is too bulky to perform backside attack, so it must wait until after the leaving group leaves to do so.

Question 8

why do large bases usually produce less substituted products?

Answer 8

the bulky base has difficulty accessing the more crowded, highly substituted carbon atoms, making it easier to abstract a hydrogen from a less substituted carbon, leading to the formation of the “Hofmann product”. the same applies vise versa.