The stereocontrolled Horner-Wittig reaction: synthesis of disubstituted alkenes

This is the authors' abstract. We don't add key points for this paper.

Addition of the lithium derivatives of phosphine oxides Ph2P(O)CH2R1 to aldehydes gives erythro adducts (11) with good stereoselectivity. Reduction of α-diphenylphosphinoyl ketones (12) gives threo adducts (11) with even better stereoselectivity. Purification by flash chromatography and/or crystallisation followed by elimination of Ph2PO2) gives pure Z- or E-alkenes with high material conversion. Explanations are offered for the stereoselectivities, conditions defined for full stereochemical control, and guidelines suggested for approaches to a given alkene.