method for preparing a polyeenverbinding a 3.7 - dimethyl - nona - 1,3,5,7 tetraeen - 1 - yi - rest contains.

摘要

A process for the preparation of polyene compounds, namely polyene compounds containing a 3,7-dimethylocta-1,3,5,7-tetraenylene radical, by reacting suitable triarylphosphonium salts with suitable aldehydes, consists in carrying out the reaction in a two-phase aqueous/organic solvent system, the organic phase being composed of an optionally chlorinated hydrocarbon which is not miscible with water and the volumetric ratio between organic phase and water being between 10:1 and 1:20. This allows extremely low reaction temperatures to be avoided without accepting low yields.