Retrosynthesis

Question 1

1,3-Hydroxyketone

Answer 1

Aldol

Question 2

1,3-Dicarbonly

Answer 2

Claisen = ester and ketone

Question 3

1,5-dicarbonyl

Answer 3

Michael = conjugated addition

Question 4

Diels-Alder

Answer 4

Reverse arrows, quote cis-Endo rules and explain regioselectivity

Question 5

1,6-diketone

Answer 5

Ozonolysis, can be done for alcohol, aldehyde/ketone or ester as long as the end product has two of the same functional groups

Question 6

1,6-hydroxycarbonyl

Answer 6

Baeyer-villager then hydrolysis to extrude O

Question 7

Umpoulung meaning

Answer 7

Inverse polarity, opposite to natural polarity

Question 8

Acyl anion umpolung equivalent

Answer 8

CN-

Question 9

1,4-hyroxycarbonyls

Answer 9

Stetter = aldehyde, α,β-unsaturated ketone and ΝaCN, one-pot reaction

Question 10

1,4-dihydroxyl compound

Answer 10

Functional group addition = add alkyne, disconnect alkyne C then Ozonolysis

Question 11

1,2-amino carboxylic acid

Answer 11

Strecker = aldehyde, NH4Cl and NaCN, one-pot reaction

Question 12

Unmask CN- to carboxylic acid

Answer 12

H+, water

Question 13

Unmask CN- to ester

Answer 13

H+ and corresponding alcohol

Question 14

Danishefsky’s diene

Answer 14

TMS as protecting group for OH to prevent keto-enol tautomerism, deprotected using acid

Question 15

Umpolung reagents for acyl anion

Answer 15

NO2, soft nucleophile, needs a guanadine base, unmasked using the Nef reaction with TiCl3 and water
Thioacetal, hard nucleophile, formed using carbonyl, SHCHH2CH2CH2SH and LA then nBuLi, unmasked using Hg(II) and water