New allylphosphonates derived from (OCH < inf > 2 < /inf > CMe < inf > 2 < /inf > CH < inf > 2 < /inf > O)PCl and Baylis-Hillman adducts - Stereochemistry and utility

Abstract

New allylphosphonates have been prepared; an X-ray structural proof for the major Z-isomer has been given for phosphonate 3. Horner-Wadsworth-Emmons reaction of 3 or 6 (Z isomer) with aromatic aldehydes leads to carbomethoxy/ cyano substituted butadienes. In the reaction using cyanoallylphosphonate 6, use of either Z or E isomer leads to the same E,Z product; stereochemistry of one such cyano product is confirmed by X-ray crystallography. In the reaction of 3 with 4-nitrobenzaldehyde stereochemistry for the (E,E) isomer is confirmed by X-ray crystallography.