Organic Mechanisms

Question 1

How to you get from alkene to alkane (Hydrogenation)?

Answer 1

Hydrogen and Nickel catalyst

Question 2

How do you get from alkene to haloalkane ( Electrophlic addition)?

Answer 2

Hydrogen halide at room temperature

Question 3

How do you get from Alkane to Haloalkane (Free Radical Substitution)?

Answer 3

Halogen and UV light

Question 4

How do you get from a haloalkane to an alcohol (Nucleophlic Substitution)?

Answer 4

NaOH (aq) or KOH (aq) and reflux

Question 5

How do you get from alcohol to haloalkane (Hydrolysis)?

Answer 5

Sodium Halide and Sulphric acid

Question 6

How do you get from an alcohol to an alkene (Dehydration) ?

Answer 6

Phosphoric acid or Sulphuric acid and heat

Question 7

How do you get from an alkene to an alcohol (Hydration)?

Answer 7

Water (steam) and Phosphoric acid

Question 8

How do you get from an alcohol to an aldehyde?

Answer 8

Acidified potassium dichromate and Sulphuric acid

Distillation

Question 9

How do you get from an alcohol to a carboxylic acid?

Answer 9

Excess acidified potassium dichromate - 2[O]
Sulphuric acid and reflux
Water is formed

Question 10

How do you get from an alcohol to a ketone?

Answer 10

Acidified potassium dichromate and Sulphuric acid

Reflux or distillation

Question 11

How do you get from an aldehyde to an alcohol?

Answer 11

Reduction
Nucleophlic addition
NaBH4 ( sodium borohydride)
Forms a primary alcohol

Question 12

How do you get from a ketone to an alcohol?

Answer 12

Reduction
Nucleophlic addition
NaBH4 (Sodium borohydride)
Forms a secondary alcohol

Question 13

How do you form an ester?

Answer 13

Esterification

1. Alcohol + Carboxylic acid
   Use concentrated and Sulphuric acid
   Forms ester and water
2. Alcohol + Acid anhydride
   Use concentrated and Sulphuric acid
   Forms ester and carboxylic acid
3. Acyl chloride + Alcohol
   Forms Ester and HCl
4. Acyl chloride + Phenol
   Forms Ester and HCl
   Irreversible and slow reaction

Question 14

What are the products of hydrolysis of an ester?

Answer 14

1. Hydrolysis in Acidic conditions
   Reflux and Dilute Sulphuric acid
   Ester + Water = Alcohol + Carboxylic acid
2. Hydrolysis in Alkaline conditions
   Reflux with KOH or NaOH
   Ester + NaOH = alcohol + carboxylate salt

Carboxylic acid can be made from:
Salt + HCl = carboxylic acid + NaCl

Question 15

How do you form an acyl chloride?

Answer 15

1. Carboxylic acid + SOCl2 at room temperature
   Forms acyl chloride, SO2 and HCl
   Dry Conditions, SOCl2 and Thionyl chloride
2. Carboxylic acid + PCl5 at room temperature
   Forms acyl chloride, POCl3, HCl
   Phosphorus (V) Chloride

Question 16

What do you add to an acyl chloride to get a carboxylic acid?

Answer 16

Water
Forms HCl too
Hydrolysis

Question 17

How do you get from a haloalkane to an amine?

Answer 17

Nucleophlic substitution
Ethanolic ammonia ( ammonia dissolved in ethanol)

Question 18

How do you get from nitrobenzene to phenylamine?

Answer 18

Reduction
Sn (Tin) and concentrated HCl
Reflux and NaOH

Question 19

How do you from an amide?

Answer 19

Acyl chloride + ammonia ( NH3)
Carboxylic acid + ammonia ( NH3)
Acyl chloride + Primary amine

Question 20

How do you get from an aldehyde or ketone to a hydroxynitrile?

Answer 20

Reduction
Nucleophlic addition
HCN and KCN (aq)

Question 21

How do you get from a haloalkane to a nitrile?

Answer 21

Nucleophlic substitution

CN ^- and ethanol

Question 22

How do you get from a nitrile or hydroxynitrile to a carboxylic acid?

Answer 22

Water/ HCl and heat
Hydrolysis
Forms ammonia too

Question 23

How do you get from a nitrile or hydroxynitrile to an amine?

Answer 23

Hydrogen and Nickel catalyst

Question 24

What is the colour change of alcohol/ to aldehyde/ketone/carboxylic acid?

Answer 24

Orange to green