Organic synthesis

Question 1

Alkane to Halogenoalkane

Answer 1

Mechanism: Free radical sub
Reagent(s): X₂
Conditions: UV light

Question 2

Halogenoalkane to alkene

Answer 2

Mechanism: elimination
Reagent(s): KOH or NaOH
Conditions: ethanolic. heat under reflux

Question 3

alkene to halogenoalkane

Answer 3

Mechanism: e- addition
Reagent(s): HBr or HCl
Conditions: room temp

Question 4

alkene to dihalogenoalkane

Answer 4

Mechanism: e- addition
Reagent(s): Br₂ or Cl₂
Conditions: room temp

Question 5

Dihalogenoalkane to Diol

Answer 5

Mechanism: Nucleophilic sub
Reagent(s): KOH
Conditions: (aq) heat under reflux

Question 6

alkene to poly(alkene)

Answer 6

Conditions: high pressure catalyst

Question 7

Halogenoalkane to nitrile

Answer 7

Mechanism: Nucleophilic sub
Reagent(s): KCN in ethanol/ water mixture
Conditions: heat under reflux

Question 8

Nitrile to primary amine

Answer 8

reduction:
LiALH4 dry ether
OR
2H₂ + Ni cat high temp and pressure

Question 9

Primary amine to secondary, tertiary or quaternary ammonium salt

Answer 9

Mechanism: Nucleophilic sub
Reagent(s): 1y amine
Conditions:

excess Haloalkane = 4y main product

Question 10

Halogenoalkane to primary amine

Answer 10

Mechanism: Nucleophilic sub
Reagent(s): alcoholic excess NH3
Conditions: heat under pressure

Question 11

Halogenoalkane to alcohol

Answer 11

Mechanism: Nucleophilic sub
Reagent(s): NaOH or KOH (aq)
Conditions: heat under reflux

Question 12

alkene to alcohol

Answer 12

Mechanism: e- addition (hydration)
Reagent(s): conc H2SO4 + steam
Conditions: (aq) 300C and high pressure 70 atm

Question 13

alcohol to alkene

Answer 13

Mechanism: elimination (dehydration)
Reagent(s): excess hot conc H2SO4, hot Al2O3 cat (lab)
Conditions: 600K

Question 14

1y alcohol to aldehyde

Answer 14

oxidation:
Reagent(s): Na2Cr2O7/H+
Conditions: heat

Question 15

2y alcohol to ketone

Answer 15

oxidation
Reagent(s): Na2Cr2O7/H+
Conditions: heat

Question 16

aldehyde to 1y alcohol

Answer 16

Mechanism: Nucleophilic addition
Reagent(s): NaBH4
Conditions: room temp

Question 17

ketone to 2y alcohol

Answer 17

Mechanism: Nucleophilic addition
Reagent(s): NaBH4
Conditions: room temp

Question 18

aldehyde or ketone to hydroxynitrile

Answer 18

Mechanism: Nucleophilic addition
Reagent(s): KCN or HCN + H2SO4
Conditions: room temp

Question 19

aldehyde to carboxylic acid

Answer 19

oxidation
Reagent(s): excess oxidising agent, Na2Cr2O7/H+
Conditions: heat under reflux

Question 20

alcohol to ester

Answer 20

esterification:
Reagent(s): carboxylic acid and H2SO4
Conditions: heat

Question 21

carboxylic acid to ester

Answer 21

esterification:
Reagent(s): alcohol + H2SO4
Conditions: Heat

Question 22

ester to carboxylic acid

Answer 22

Reagent(s): dilute H2SO4 catalyst + H2O
Conditions: reflux

Question 23

primary amine to secondary amide

Answer 23

Mechanism: Nucleophilic addition
Reagent(s): acyl chloride
Conditions: room temp

Question 24

secondary amide to acyl chloride or acid anhydride

Answer 24

Mechanism: Nucleophilic add elim
Reagent(s): primary amine
Conditions: room temp

Question 25

acyl chloride or acid anhydride to carboxylic acid

Answer 25

Mechanism: Nucleophilic add elim Reagent(s): H2O Conditions: room temp

Question 26

acyl chloride or acid anhydride to N-substituted amide

Answer 26

Mechanism: Nucleophilic add elim Reagent(s): amine Conditions: room temp

Question 27

acyl chloride or acid anhydride to primary amide

Answer 27

Mechanism: Nucleophilic add elim Reagent(s): NH3 Conditions: room temp

Question 28

Benzene to Nitrobenzene

Answer 28

Mechanism: e- sub Reagent(s): HNO3 + H2SO4

Question 29

eqn for formation of nitronium electrophile

Answer 29

HNO3 + 2H2SO4 --> NO2+ + 2HSO4- + H3O+

Question 30

Benzene to phenyl ethanone

Answer 30

Mechanism: e- sub Reagent(s): Acyl chloride + ALCl3 cat

Question 31

eqn for formation of acylium electrophile

Answer 31

AlCl3 + CH3COCl --> [CH3CO]+ + [AlCl4]-

Question 32

Nitrobenzene to phenyl amine

Answer 32

reduction Reagent(s): Sn + conc HCl then NaOH

Question 33

Phenylamine to N-methyl benzenamine

Answer 33

Mechanism: Nucleophilic sub Reagent(s): CH3Cl

Question 34

N-methyl benzenamine to N-phenyl ethanomide

Answer 34

Mechanism: Nu add elim Reagent(s): CH3COCl

Answer 35

Mechanism: Nu add Reagent(s):

Answer 36

reduction Reagent(s): LiALH4 OR 2H2 + Ni cat

Answer 37

Mechanism: Nu add Reagent(s): NaBH4 (reduction)

Answer 38

esterification: Reagent(s): H2SO4 + CH3COOH Conditions: heat