Stereochemical control (E/Z and syn/anti) by the diphenylphosphinoyl group in the synthesis of allylic alcohols by allylic rearrangement and by 1,4-diastereoselective reduction of enones

Abstract

Allylic rearrangement of substitued 2-hydroxyalk-3-en-1-yl(diphenyl)phosphine oxides to 4-hydroxyalk-2-en-1-yl(diphenyl)phosphine oxides can be performed with total regio- and reasonable stereochemical control. Alternatively, the reduction of substituted 4-diphenylphosphinoylbut-2-en-1 -ones shows remarkable 1,4-diastereoselectivity. All these reactions are directed by the diphenylphosphinoyl (Ph₂PO) group.