A new general method of resolving racemic alcohols and its application to (<i>rs</i>)‐2‐hydroxy‐2‐(3‐phenoxyphenyl)acetonitrile and (<i>rs</i>)‐allethrolone

Abstract

Abstract The preparation is described of pure ( S )‐2‐hydroxy‐2‐(3‐phenoxyphenyl)acetonitrile (the alcohol component of some very active pyrethroids) from the racemic form of this 2‐hydroxyacetonitrile. The new resolution process is based on differences in physical properties of two diastereoisomeric ethers. The resolving agents used are chiral hemiacetal compounds; one of these, 4‐hydroxy‐6,6‐dimethyl‐3‐oxabicyclo[3.1.0]hexan‐2‐one, is available from an industrial synthesis of chrysanthemic acid, and appears specially useful for a two‐step resolution of many racemic alcohols, even base‐sensitive types.