Studies on organophosphorus compounds 104. Reaction of carbanions derived from alkylphosphonates

Structural effect of substituents directly bonded to carbanions bearing a p hosphonate moiety is examined. Nucleophilic addition of phosphonate carbani on to 1-nitroalkene followed by subsequent reaction with chlorotrimethylsil ane leads to a series of 2-isoxazoline based on the formation of an alkene and silyl nitronate as a 1,3-dipole. On the other hand, addition of carbani on derived from isocyanomethylphosphonate to nitroalkene with the formation of nitronate followed by intromolecular cyclization provides substituted p hosphoryl pyrroles.