A Guidebook to Mechanism in Organic Chemistry

Addition to Carbon-Carbon Double Bonds

O^9 ®Q/ X>^9

and, in support of this view, it is found that the additions catalysed

by Lewis acids such as BF 8. The primary addition product (mol-

ozonide) probably has the structure shown above, but it enjoys only

a transient existence and is found to dissociate readily into two

fragments:

(XXXI)

Th$se^ragments m^ recombine to form the normal end-product

(XXXII) of the reaction, generally called the iso-ozonide

^>o—o o—o

(XXXII)

but the peroxy zwitterion (XXXI) may also undergo alternative

reactions, e.g. self-addition to yield a dimer:

O—O

K X

o-o

When ozonisation is carried out, either prepajatively or diag-

nostically, in order to cleave a carbon-carbon double bond

^>C=C<^ -—> ^>c==o+o=C<^