Convenient syntheses of biologically relevant vinyl and divinyl phosphatesby selective dealkylation of the corresponding phosphites

Reactions of diethyl vinyl phosphite and divinyl methyl phosphite with iodi ne produce exclusively dealkylated intermediates, the highly reactive vinyl and divinyl phosphoroiodidates, which can be used as efficient phosphoryla tion reagents to prepare a variety of vinyl and divinyl organophosphorus co mpounds. Examples are given for the ethyl vinyl and divinyl analogs of the potent diethyl phosphate anticholinesterase agents diazoxon, chlorpyrifos o xon and paraoxon.