Retrosynthesis

Question 1

Chemoselectivity

Answer 1

Which group reacts

Question 2

Regioselectivity

Answer 2

Where will it react

Question 3

How do epoxides react under basic conditions

Answer 3

Sn2 and attacked at less hindered

Question 4

How do epoxides react under acidic conditions

Answer 4

SN1 forms more stable C+

Question 5

What happens if a synthon doesn’t have a stable anion reagent

Answer 5

Use Grignard

Question 6

How are alkenes made

Answer 6

Dehydration of alcohols, wittig and reduction of alkynes

Question 7

What is a good activating group

Answer 7

CO2Et

Question 8

What’s a good protecting group

Answer 8

Acetal OHCH2CH2OH

Question 9

How are aromatic ketones made

Answer 9

Friedel Crafts acylation

Question 10

1,3-hydroxycarbonyls

Answer 10

Aldol, disconnect next to OH group

Question 11

Alpha, beta-unsaturated carbonyls

Answer 11

Add water across double bond

Question 12

1,3-dicarbonyls

Answer 12

Claisen

Question 13

1,5-dicarbonyls

Answer 13

Michael addition

Question 14

1,3-disconnections

Answer 14

Can be made by conjugate addition but only works with soft nucleophiles

Question 15

What do amines need to retrosynthesis

Answer 15

Functional group interconversion

Question 16

How would you dehydrate an alcohol

Answer 16

H2SO4 and heat

Question 17

What’s used for claisen if both have enolisalbe alpha-H

Answer 17

Enamine which then needs acid chloride as it’s not as reactive as envolâtes

Question 18

How would you remove acetal protective group

Answer 18

Aqueous acidic work up

Question 19

Reagents for friedel-crafts acylation

Answer 19

(Substituted) benzene and acid chloride gives para substituted

Question 20

When is Wittig used

Answer 20

instead of alpha, beta-unsaturated when both have enolisable alpha H

Question 21

What is used to make ketones

Answer 21

Weinreb aminde and grignard

Question 22

Base used to deprotonate alcohols

Answer 22

NaH