Synth fest regioselectivity

Question 1

HBr addition to db

Answer 1

ionic mechanism on more subbed
radical mechanism on less subbed

Question 2

Double bond hydration

Answer 2

Oxymercuration/reduction on more subbed C
Hydroboration on less subbed

Question 3

Baeyer-Villager oxidation
(Oxidation of ketones to esters)

Answer 3

Oxygen subbed between more subbed alpha carbon + carbonyl group
MCPBA required

Question 4

Beckmann rearrangement
(insertion of N next to carbonyl to make amide)

Answer 4

Group which migrates is trans to OH group
NH2OH to make oxime (C=N)
H2SO4 alkyl migration to N, H2O added to pos charge on double bond to give carbonyl

Question 5

Enones

Answer 5

Strongly basic- 1,2 addition e.g LiAlH4, RLi
Weakly basic- 1,4 addition e.g stable enolates, cuprates R2CuLi, NaBH4/CuI

Question 6

Addition of Nu to epoxide

Answer 6

basic conditions, Nu attacks less hindered side
acidic conditions, Nu attacks more hindered side

Question 7

Alkynes to alkenes

Answer 7

H2 and lindlar catalyst gives Z
i) Na, NH3(l), ii) H2O gives E

Question 8

What is MCPBA used for?

Answer 8

Oxidation of ketones to esters. (Baeyer-villager)