Additions of lithiated β-hydroxy alkyldiphenylphosphine oxides to aldehydes, and palladium(II)-catalysed allylic transpositions of bis-acetoxy alkyldiphenylphosphine oxides: synthesis of O-protected (E,E)- and (E,Z)hepta-2,4-dien-1-ol and of alkyldiphenylphosphine oxides bearing remotely related chiral centres

Abstract

Saturated and unsaturated β- and δ-hydroxyalkyldiphenylphosphine oxides give adducts with aldehydes after treatment with an excess of butyllithium. Normal Horner–Wittig reactions lead to O-trityl (E,E)- and (E,Z)-hepta-2,4-dien-1-ols. Allylic rearrangement of the corresponding acetates catalysed by Pd^II can be used to control remote (1,4 or 1,7) relative stereochemistry across E alkenes.