Advices For Studying Organic Chemistry

formation of an epoxide and a carboxylic acid.

3. Most often used peroxy acids for epoxidation:

1) MCPBA: Meta-ChloroPeroxyBenzoic Acid (unstable).

ate.

2) MMPP: Magnesium MonoPeroxyPhthal

Cl C O

O

OH

2

Mg2+

C O

−

O

C O

O

OH

m-Chloroperoxybenzoic acid Magnesium monoperoxyphthalate
(MCPBA) (MMPP)

4. Example:
   H
   O
   H

MMPP

CH 3 CH 2 OH

1,2-Epoxycyclohexane

85%

(cyclohexene oxide)

Cyclohexene

5. The epoxidation of alkenes with peroxy acids is stereospecific:
   
   
   1. cis-2-Butene yields only cis-2,3-dimethyloxirane; trans-2-butene yields only the
      racemic trans-2,3-dimethyloxiranes.
   
   
   
   

C

HCH

+

O

C O

3

H 3 CH

R CO H

cis-2-Butene cis-2,3-Dimethyloxirane

O

H 3 C CH 3

H H

(a meso c ound)

omp