The OSM (oxidation state modification) concept: Application to a new and rapid synthesis of retinoids

Abstract The OSM (oxidation state modification) concept for the elaboration of new synthetic pathways is demonstrated for the synthesis of β-ionylidene acetaldehyde 11 and retinal 13 . According to this new scheme, electrophilic addition to ω-heterosubstituted enol ethers 5 of the cationic species 9 , generated from β-ionol led to aldehydic intermediates 10 which undergo easy elimination to β-ionylidene acetaldehyde 11 . Similarly, retinal 13 was obtained from vinyl-β-ionol 14 and dienol ethers 12 , via aldehydes 16 .