Highly Stereoselective Nucleophilic Addition of Difluoromethyl‐2‐pyridyl Sulfone to Sugar Lactones and Efficient Synthesis of Fluorinated 2‐Ketoses

Abstract

Abstract Nucleophilic addition of difluoromethyl‐2‐pyridyl sulfone to sugar lactones proceeded with good yield and excellent stereoselectivity. The hitherto unknown direct addition intermediates are stable and capable of useful conversions: Formal elimination of the anomeric hydroxy and sulfonyl groups yielded a 1‐deoxy‐1‐difluoromethylene mannopyranose derivative. Directly from sugar lactones, by nucleophilic addition and subsequent one‐pot reduction with allylmagnesium chloride, unprecedented fluorinated 2‐ketose analogues were prepared efficiently.