Synthetic Routes

Question 1

Alkane to haloalkane

Answer 1

Free radical substitution
Br2, Cl2, etc
UV light

Question 2

Haloalkane to alcohol

Answer 2

Nucleophilic substitution
Aqueous KOH or NaOH
Heat under reflux

Question 3

Haloalkane to nitrile

Answer 3

Nucleophilic substitution
Heat under reflux with KCN dissolved in ethanol

Question 4

Haloalkane to primary amine to secondary amine

Answer 4

Nucleophilic substitution
Heat under reflux with (excess) NH3 dissolved in alcohol

Question 5

Haloalkane to alkene

Answer 5

Elimination
Heat under reflux with ethanolic KOH

Question 6

Alkene to polyalkene

Answer 6

High pressure
Catalyst

Question 7

Alkene to haloalkane

Answer 7

Electrophilic addition
HCl, HBr
Room temp

Question 8

Alkene to dihalogenoalkane

Answer 8

Electrophilic addition
Cl2, Br2
Room temp

Question 9

Dihalogenoalkane to diol

Answer 9

Nucleophilic substitution
Aqueous KOH
Heat under reflux

Question 10

Alcohol to alkene

Answer 10

conc. H2SO4 or conc. H3PO4
Elimination, dehydration

Question 11

Alkene to alcohol

Answer 11

Step 1: Electrophilic addition with H2SO4
Step 2: H2O warm hydrolysis

Question 12

partial oxidation of primary alcohol

Answer 12

acidified potassium dichromate (VI) solution
heat and distill
aldehyde forms

Question 13

complete oxidation of primary alcohol

Answer 13

acidified potassium dichromate (VI) solution
heat under reflux
carboxylic acid forms

Question 14

oxidation of secondary alcohol

Answer 14

heat with acidified potassium dichromate (VI) solution
forms ketone

Question 15

why can’t tertiary alcohols not be oxidised

Answer 15

there is no H atom attached to the carbon with the -OH group

Question 16

aldehyde to alcohol
what type of alcohol forms

Answer 16

reduction with sodium borohydride (NaBH4)
nucleophilic addition
primary alcohol

Question 17

ketone to alcohol
what type of alcohol forms

Answer 17

reduction with sodium borohydride (NaBH4)
nucleophilic addition
secondary alcohol

Question 18

alcohol to ester

Answer 18

carboxylic acid

conc H2SO4 catalyst
HCl gas used if benzene ring present

Question 19

aldehyde to hydroxynitrile
why does this form enantiomers

Answer 19

nucleophilic adition
NaCN and H2SO4

Chiral carbon and planar C=O bond

Question 19

Name the mechanism and reagent for ketone to hydroxynitrile
when/why would this form enantiomers?

Answer 19

nucleophilic addition
KCN

If the ketone is asymmetrical, the C=O bond is planar and can be attacked by the nucleophile from either side

Question 20

carboxylic acid to ester

Answer 20

heat with alcohol in the presence of H2SO4 catalyst

Esterification

Question 21

Acyl chloride/acid anhydride to ester

Answer 21

alcohol
room temp
nucleophilic addition-elimination

Question 22

Acyl chloride/acid anhydride to carboxylic acid

Answer 22

H2O
room temp
nucleophilic addition-elimination

Question 23

Acyl chloride/acid anhydride to secondary amide

Answer 23

primary amine
room temp
nucleophilic addition-elimination

Question 24

Acyl chloride/acid anhydride to primary amide

Answer 24

NH3 room temp nucleophilic addition-elimination

Question 25

hazards of using KCN / HCN

Answer 25

KCN reacts with moisture in air to form HCN, which is toxic to humans HCN is hard to store and produces dangerous byproducts

Question 26

Name the mechanism for benzene Outline 2 reactions it undergoes, with reagents and conditions

Answer 26

electrophilic substitution Nitration -conc HNO3 and conc H2SO4 -heat under reflux at 50 degrees Celsius -yellow dry nitrobenzene forms Friedel-Crafts Acylation -heat under reflux at 50 degrees Celsius -react with alkyl or acyl halides in the presence of a strong Lewis acid (e.g. AlCl3)