A simple procedure for the synthesis of 2,3-unsaturated glycosides in acetonitrile and tetrahydropyranylation of alcohols and phenols in dichloromethane in the presence of 3,5-dinitrobenzoicacid is described. A variety of alcohols and thiols are reacted with glycals to give the desired products in high yields with high α-selectivity.
Scope of AuCl3 in the activation of per-O-acetylglycals
作者:Rengarajan Balamurugan、Srinivasa Rao Koppolu
DOI:10.1016/j.tet.2009.07.087
日期:2009.9
Gold(III)chloride in catalytic amounts activates 3,4,6-tri-O-acetyl-D-glucal, 3,4,6-tri-O-acetyl-D-galactal, and 3,4-di-O-acetyl-L-rhamnal efficiently. The activated species can be employed in the Ferrier reaction with different nucleophiles at ambient conditions. Attempts have been made to make beta-anomer of the Ferrier product from anomeric-O-propargylated Ferrier product. (C) 2009 Elsevier Ltd. All rights reserved.