Bis(acylsilanes) and trifluoromethyltrimethylsilane: A useful system for the synthesis of cyclic 2,2-difluoro-3-trialkylsilyl-1,3-ketols and cyclic 2-fluoro-1,3-diketones

We report a one-pot reaction of bis(acylsilanes) with trifluoromethyltrimet hylsilane (TFMTMS) leading to a new family of 2,2-difluoro-3-trialkylsilylk etols 4. These compounds were submitted to a facile and effective defluoros ilylation. The overall process constitutes a new synthesis of cyclic six- a nd seven-membered 2-fluoro-1,3-diketones 8, with regiospecific introduction of fluorine. The keto-enol equilibrium of cyclic 1,3-diketones and the mec hanism of the defluorosilylation reaction were also studied.