Advices For Studying Organic Chemistry

General Reaction

C

C

+

C

C

+

H

H

H

H

2 H 2 C

C

HH

HH

Alkyne Alkane

Pt, Pd, or Ni

solvent,

pressure

C

C

Pt, Pd, or Ni

solvent,

Alkene Alkane

pressure

2) The reaction is usually carried out by dissolving the alkene or alkyne in a solvent

such as ethyl alcohol (C 2 H 5 OH), adding the metal catalyst, and then exposing the

mixture to hydrogen gas under pressure in a special apparatus.

Specific Examples

CH 3 CH CH 2 + HH

H H

Ni CH 3 CH CH 2

propene propane

(25 oC, 50 atm)

C 2 H 5 OH

C

CH 3

H 3 C CH 2 + C

CH 3

H 3 C CH 2

HH

HH

2-Methylpropene Isobutane

Ni

(25 oC, 50 atm)

C 2 H 5 OH

+ H 2

Cyclohexene Cyclohexane

Ni

(25 oC, 50 atm)

C 2 H 5 OH

• 2 H (^2) ethyl acetatePd O
  5-Cyclononynone Cyclononanone
  O

4.18B REDUCTION OF ALKYL HALIDES

1. Most alkyl halides react with zinc and aqueous acid to produce an alkane.