Advices For Studying Organic Chemistry

3. An SN2 reaction:

RC C − C Br

R'

HH

CH 2 R'

Na+

substitution

nucleophilic

SN 2

RC C +NaBr

Sodium

alkynide

1 o Alkyl

halide

4. This synthesis fails when secondary or tertiary halides are used because the
   alkynide ion acts as a base rather than as a nucleophile, and the major results is an
   E2 elimination.

RC C −

C Br

C

R''

H

H R' H

H

E2 RC C + R'CH CHR'' + Br

−

2 o Alkyl halide

7.13 HYDROGENATION OF ALKENES

1. Catalytic hydrogenation (an addition reaction):
   
   
   1. One atom of hydrogen adds to each carbon of the double bond.
   
   
   2. Without a catalyst the reaction does not take place at an appreciable rate.
   
   
   
   

CH 2 =CH 2 + H 2

25 oC

Ni, PdorPt CH

3 –CH 3

CH 3 CH=CH 2 + H 2 Ni, P 25 doCorPt CH 3 CH 2 –CH 3

2. Saturated compounds:


3. Unsaturated compounds:


4. The process of adding hydrogen to an alkene is a reduction.