·     

In case of cyclic alkenes that are conformationally rigid, the reagent approaches from the less hindered side of the double bond. This is illustrated in the oxidation of norbornene (Scheme 4).

Scheme 4

Scheme 5

The isolated alkenes undergo reaction before the conjugated double bond. This is illustrated by the oxidation of b-myrcene (Scheme 5).
A suitable substituent particularly at the allylic position may control the direction of the new epoxide group (Scheme 6). This is due to the transition state electronic interaction between electron deficient m-CPBA and the direction group.

Scheme 6

Mechanism

 The reaction proceeds through a concerted pathway (Scheme 7). The reaction involves addition of an oxygen atom to the double bond with simultaneous proton transfer from oxygen to carbonyl oxygen.

Scheme 7

1.5.3 Oxidation of Amines

The tertiary amines and the aromatic nitrogen containing heterocycles could be oxidized to the corresponding N-oxides using peracids, which have great synthetic utility (Scheme 8-9). The aromatic primary amines are oxidized to aromatic nitro compounds.

Scheme 8

Scheme 9