Preparation of Optically Active Flowery and Woody-Like Odorant Ketones via Corey-Chakovsky Oxiranylation: Irones and Analogues

Christian Chapuis and Robert Brauchli

In an article about different irones preparations and analogues optically active,
Chapuis described the first enantioselective synthesis of (-)-cis-g-Irone.

Reagents : a) Me3SI, DMSO, NaOH; b) SnCl4, toluene; c) Ph3P=CHCOCH3, toluene

Chapuis obtained a trans / cis mixture, only separable by preparative GC.