Synthesis of spirophosphoranes containing a phosphorus–carbon bond using the reactions of substituted benzo[d]-1,3,2-dioxaphospholes with diethyl acetylenedicarboxylate

The reaction of 2-(2-oxo-1,2-diphenyl)ethoxy- and 2-(2-methylcarbonyl)phenyloxybenzo[d]-1,3,2- dioxaphospholes with diethyl acetylenedicarboxylate was used to synthesise 5,6-bis(ethoxycarbonyl)-3,4-diphenyl-1,1-phenylenedioxy-1-phospha-2,7-dioxabicyclo[2.2.1^1,4]hept-5-ene and 5-methyl-6,7-bis(ethoxycarbonyl)-1,1-phenylenedioxy-3,4-benzo-1-phospha-2,8-dioxabicyclo[3.2.1^1,5]oct-6-ene in high yields.