synthesis

Question 1

alkene to dihalogenoalkane

Answer 1

X2; room temp

Question 2

alkene to halogenoalkane

Answer 2

HX; bubble through at room temp

Question 3

alkene to diol

Answer 3

acidified KMnO4; water

Question 4

alkene to alkane

Answer 4

H2; heat 150 degrees; nickel catalyst

Question 5

alkene to alcohol

Answer 5

steam; acid catalyst

Question 6

halogenoalkane to alcohol

Answer 6

aq KOH; heat under reflux (nucleophilic sub)

or

ethanolic water

or

Mg + dry ether; then ketone / aldehyde; then dilute acid (grignard)

Question 7

halogenoalkane to nitrile

Answer 7

ethanolic KCN; heat under reflux

Question 8

halogenoalkane to alkene

Answer 8

ethanolic KOH; reflux

Question 9

halogenoalkane to primary amine

Answer 9

excess ethanolic ammonia; heat + pressure in a sealed tube

Question 10

alcohol to ketone / aldehyde

Answer 10

acidified potassium dichromate; heat and distill as products form

Question 11

aldehyde to carboxylic acid

Answer 11

acidified potassium dichromate; heat under reflux

or

tollens reagent; heat

or

fehling solution; heat

Question 12

carboxylic acid to alcohol

Answer 12

LiAlH4 in dry ether

Question 13

carboxylic acid to acyl chloride

Answer 13

PCl5 at room temp

Question 14

acyl chloride to carboxylic acid

Answer 14

cold water

Question 15

acyl chloride to amide

Answer 15

NH3 for primary; amine for secondary / tertiary

Question 16

acyl chloride to ester

Answer 16

alcohol

Question 17

carboxylic acid to ester

Answer 17

alcohol; heat with acid catalyst

Question 18

alkane to halogenoalkane

Answer 18

halogen; UV light (free radical sub)

Question 19

alcohol to halogenoalkane

Answer 19

KBr; 50% sulfuric acid

or

PCl5; room temp

or

HCl; room temp

or

iodine + red phosphorus

Question 20

ketone / aldehyde to hydroxynitrile

Answer 20

ethanolic HCN + KCN; reflux (nucleophilic addition)

Question 21

halogenoalkane to carboxylic acid

Answer 21

Mg + dry ether; then CO2; then dilute acid (grignard)

Question 22

benzene to alkylbenzene

Answer 22

chroroalkane / acyl chloride; dry AlCl3 halogen carrier catalyst (same with bromine)

Question 23

benzene to cyclohexane

Answer 23

hydrogen; heat with nickel catalyst

Question 24

benzene to bromobenzene

Answer 24

bromine Br2; dry FeBr3 halogen carrier catalyst

Question 25

benzene to nitrobenzene

Answer 25

warm conc HNO3 (base) + H2SO4 (acid)

Question 26

nitrobenzene to phenylamine

Answer 26

HCl; Sn catalyst (reduction)

Question 27

phenol to tribromophenol

Answer 27

Br2

Question 28

nitrile to primary amine

Answer 28

LiAlH4 in dry ether

or

hydrogen + nickel catalyst

Question 29

ester to carboxylic acid

Answer 29

dilute acid under reflux

or

dilute alkali under reflux; then add HCl (both hydrolysis)

Question 30

nitrile to carboxylic acid

Answer 30

dilute acid under reflux

or

dilute alkali under reflux; then add HCl (both hydrolysis)

Question 31

alcohol to alkene

Answer 31

conc H3PO4 (dehydration)

Question 32

what is a ‘grignard reagent’

Answer 32

R-MgX; product of halogenoalkane and Mg in dry ether

Question 33

what happens in the main grignard reaction

Answer 33

carbonyl / CO2’s C=O converted to R-C-O-MgX

Question 34

why is dilute acid added in a grignard reaction

Answer 34

to replace C-O-MgX with C-OH

Question 35

what are the steps of recrystallisation

Answer 35

dissolve in min vol of hot solvent; hot filter - remove insoluble impurity; cool in ice bath; cold vacuum filter; wash with cold water - remove soluble impurity; dry in a nice warm oven