Synthesis and stereoselectivity of a new type of unsaturated phosphonates

Abstract

A series of unsaturated phosphonates 2, 3, 4 with structures similar to that of abscisic acid (ABA) were synthesized by the Wittig-Horner reactions of bisphosphonylmethane 1 with β-substituted propenals, propargyl aldehydes or α,β-unsaturated methyl ketones. Compounds 5 were prepared by the Michaelis-Becker reactions of ω-bromodienes 7 with sodium phosphites. Compounds 7 were obtained by the phase transfer Wittig reactions of ω-bromobutylphosphonium salt 6 with β-substituted propenals. The structures of all new compounds prepared were characterized by 1H NMR, 31P NMR, IR spectra, and elemental analysis or MS. The stereochemistry of the Wittig reactions was studied. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:261–266, 2000