Preparation of Alkenes

Question 1

Reactant: Alkynes
Reagent(2)? Pdt?

Answer 1

a) Lindlar’s catalyst:
Pd/H2-CaCO3/Quonoline
Pdt: Cis alkene
——————————————–
b)Birch Reaction:
Na+NH3
Pdt: Trans alkene

Question 2

Reactant: Alkyl Halides
Reagent(1)? Pdt?

Answer 2

Dehydrohalogenation(B elimination)
Reagent: Alc. KOH and Heat
Pdt: Alkene( No rearrangement)

Question 3

Reactant: Vicinal Dihalide
Reagent(1)? Pdt?

Answer 3

Aka Dehalogenation
Reagent: Zn, Heat
Pdt: Alkenes

Question 4

Reactant: Alcohols
Reagent(1)? Pdt?

Answer 4

Dehydration of alcohol
Reagent: Conc. H2SO4 or Anhydrous Al2O3
Pdt: Alkene(Rearrangement possible)

Question 5

Reactant: Sodium Salt of acid
Reagent(1)? Pdt?

Answer 5

Reagent: NaOH, Electrolysis
Pdt: Alkenes

Question 6

Reactant: Esters
Reagent(1)? Pdt?

Answer 6

Reagent: Heat
Pdt: Hoffman dominates
(H lost from B)

Question 7

Reactant: Quatenary salt
Reagent(1)? Pdt?

Answer 7

Reagent: Heat, OH-
Pdt: Hoffman dominates
(H lost from B)