The synthesis and chemistry of formylphosphonate

New methods of synthesis and reactions of formylphosphonate have been inves tigated. Attempts to deprotect the corresponding diethyl acetal with Ti-IV halides led instead to the formation of halo(ethoxy)methylphosphonates whic h undergo substitution reactions with a wide range of nucleophiles. The pro ducts of reactions of formylphosphonate with bifunctional nucleophiles are determined in most cases by Baldwin's Roles, while the imines derived from formylphosphonate undergo Diels-Alder reactions only in those cases which c arry a strongly electron-withdrawing N-substituent.