Synthesis and spectral properties of fluorinated α,β-epoxyphosphonates

Two strategies for the synthesis of the monofluorinated α,β-epoxyphosphonates 4 and 13 have been applied. The electrophilic monofluorinations of enamine 1 or β-enaminophosphonate 6 using Selectfluor® or chlorofluorination of 6 with Selectfluor® and NCS have been evaluated. The synthesis of intermediates fluorohaloketones 3, 8 and 9 and fluorohalohydrins 10 and 11 have been accomplished. The nucleophilic attack to CO ketone bond of 3 gave desired α,β-epoxyphosphonate 4 whereas base treatment of fluorohalohydrins 10 and 12 gave oxirane 13 or phosphates 14 or 15. The product structures were confirmed by 1H, 13C, 19F and 31P NMR spectroscopy.