NEW SYNTHESIS OF ISOXAZOLIDINES

摘要

A new synthesis of 5-substituted isoxazolidines was developed by direct isoxazolidine ring formation of allylic hydroxylamines under acidic conditions. The cyclization process is an electrophilic S(N)1 type reaction. The formed carbocation intermediate is stabilized by electron rich groups (ie., phenyl). A moiety that mediates oxonium ion formation (i.e., para-methoxy) accelerates the rate of product formation. [References: 5]