Stereoselective Synthesis of C‐Glycoside with a Glycosyl Dianion

Abstract

No elimination of the functional group at position 2 occurs when the dilithio compound 1 reacts with a range of electrophiles “E⊕”, for example aldehydes and methyl iodide, to give α-C-glucosides 2. Thus the flexible concept of C-elongation of pyranoses by umpolung at the anomeric center may be used for the direct synthesis of the 2-hydroxy compounds.