Synthetic Routes

Question 1

Alkane to Alkene

Answer 1

Cracking,

Al2O3 very high temperature (500*C)

Question 2

Alkene to Alkane

Answer 2

Hydrogenation,
Add H2,
Ni catalyst, high temperature (150*C)

Question 3

Halogenoalkane to Alkene

Answer 3

Elimination,
Add KOH,
Ethanol Reflux

Question 4

Alkene to Halogenoalkane

Answer 4

Halogenation/ Electrophilic addition, room temp.
Add X2 -> dihalo
Add H-X -> halo

Question 5

Halogenoalkane to Alcohol

Answer 5

Hydrolysis/ Nucleophilic substitution,
Add NaOH/KOH,
Relfux, Ethanol Water

Question 6

Alcohol to Halogenoalkane

Answer 6

Halide subsitution/ Nucleophulic substitution,
Add HBr,
Heat (H2O lost)

Question 7

Alcohol to Alkene

Answer 7

Dehydration,
Strong acid (H2SO4/H3PO3) and high temp,
(Gives water)

Question 8

Alkene to Alcohol

Answer 8

Hydration,
Steam,
SiO2 + phosphoric acid, (300*C)

Question 9

Alcohol to Aldehyde

Answer 9

Primary Alcohol,
Oxidation (O),
Distillation (to prevent further oxidisation),
dripped into K2Cr2O7

Question 10

Alcohol to Carboxylic Acid

Answer 10

Primary Alcohol,

Oxidation under relfux, (on from aldehyde)

Question 11

Alcohols to Ketones

Answer 11

Secondary Alcohol,
Oxidation,
(creates Water)

Question 12

Alcohol to Ester

Answer 12

Esterification,
Add Carboxylic acid,
Strong acid catalyst,

Question 13

What causes a halogenoalkane to become an alkene (elimination) or an alcohol (Nuc. Substitution)?

Answer 13

Primary Alcohol-Substitution
Tertiary Alcohol-Elimination

Water encourages substitution
Ethanol encourages elimination

Higher temp and conc - elimination