A Highly Stereoselective Synthesis of 1,2‐<i>trans</i>‐C‐Glycosides via Glycosyl Samarium(<scp>III</scp>) Compounds

Abstract

Remarkably stable even at room temperature towards elimination are the 1,2-trans-glycosyl samarium(III) species of type 2. The stability of these species, which contrasts sharply with that of glycosyl lithium counterparts, is the decisive factor for the high 1,2-trans selectivity of the synthesis of the C-glycoside 3 by reductive samariation of anomeric sulfones of type 1 in the presence of carbonyl compounds.