Stereochemical and chiral aspects in the synthesis of 3‐(2,2‐ dihalovinyl)‐2,2‐dimethylcyclopropanecarboxylic acids

Abstract

Abstract The synthesis of (1 RS )‐ cis,trans ‐3‐(2,2‐dichlorovinyl)‐2,2‐dimethylcyclopropanecarboxylic acid by dehydrohalogenation of 4,6,6,6‐tetrahalohexanoates has been modified to produce stereo‐selectively the cis ‐isomer. A new stereospecific synthesis of cis ‐3‐(2,2‐dihalovinyl)‐2,2‐dimethylcyclopropanecarboxylic acids using a bicyclic lactone and its extension to the preparation of the optically active (1 R )‐ cis acid are described.