Second-generation synthesis of protected phosphonothiodifluoromethylene analogues of nucleoside-3′-phosphates

A practical, eight-step synthesis of the key intermediate in 19% overall yield from α-d-xylose is described. The preparation can be carried out on multi-gram scale and involves the use of the organomagnesium reagent . The capability of derivative to be transformed into the title compounds is examplified by the preparation of . Additionally, X-ray crystallography of intermediate provided the first structural data on difluorophosphonothioates.