Oxaphosphetane Definition:

An intermediate that is believed to be formed during Wittig reactions.

Oxaphosphetane Explained:

Organophosphorus ylides react with aldehydes or ketones to give substituted alkenes in a transformation called the Witt reaction.  This reaction is named for George Wittig who was awarded the Nobel prize for this work in 1979.  A principal advantage of alkene synthesis by the Wittig reaction is that the location of the double bond is absolutely fixed, in contrast to the mixtures often produced by alcohol dehydration.