Regio- and Stereoselective Organocatalyzed Relay Glycosylations To Synthesize 2-Amino-2-deoxy-1,3-dithioglycosides
Yongyong Wan, Meimei Zhou, Liming Wang, Kexin Hu, De-Yong Liu, Hui Liu, Jiansong Sun, Jeroen D. C. Codée, Qingju Zhang
Abstract
Herein, we describe a novel methodology for the regio- and stereoselective convergent synthesis of 2-amino-2-deoxy-dithioglycosides via one-pot relay glycosylation of 3- O -acetyl-2-nitroglucal donors. This unique organo-catalysis relay glycosylation features excellent site- and stereoselectivity, good to excellent yields, mild reaction conditions, and broad substrate scope. 2-Amino-2-deoxy-glucosides/mannosides bearing 1,3-dithio-linkages were efficiently obtained from 3- O -acetyl-2-nitroglucal donors in both stepwise and one-pot glycosylation protocols. The dithiolated O-antigen of E . coli serogroup 64 was successfully synthesized using this newly developed method.