New Entry to the C-Glycosilation by means of Carbenoid Displacement Reaction. Its Application to the Synthesis of Showdomycin

Article abstract of DOI:10.1021/ja00244a024

The novel and stereoselective carbon-carbon bond-forming reaction at the anomeric center of carbohydrates has been developed by means of a carbenoid displacement reaction with phenyl thioglycosides.This reaction was suggested to proceed via the oxonium ion intermediates and has the following advantages: (i) the preferential participation of a carbenoid with a sulfur atom can restrict the reaction site; (ii) the reaction can be carried out under neutral reaction condition; and (iii) the introduction of various functionalities can be accomplished by manipulation of the organosulfur groups of the products.This synthetic strategy was successfully applied to the synthesis of antitumor agent, (+)-showdomycin, and would provide a general route to the other C-glycosides.