Process for preparing (s)- and (r) -but-3-en-2-ol and the derivatives thereof from l-or d-lactic acid esters

摘要

A novel process for preparing enantiomerically pure (S)- or (R)-but-3-en-2-ol compounds includes the following reaction steps: (a) reacting an alkyl ester of D- or L-lactic acid with a hydropyran compound to obtain a lactate ester having a hydropyranyl ether group, (b) reducing the lactate ester with an aluminum hydride at a temperature below 0 DEG C. to obtain a propionaldehyde having a hydropyranyl ether group, (c) reacting the propionaldehyde with an alkyl phosphonium salt to obtain a 3-butene having a hydropyranyl ether group, and (d) cleaving the hydropyranyl ether group to prepare the enantiomerically pure (S)- or (R)- but-3-en-2-ol.