Novobiocin-related compounds: synthesis of 3-benzoylamino-2-oxo-2H-1-benzopyran-7-yl D-glycopyranosides by the trichloroacetimidate methodology

A general stereoselective method for the synthesis of 4-deoxynovobiocin-rel ated glycosides is described. 3-Benzoylamino-2H-1-benzopyran-7-yl 2,3,4,6-t etra-O-acetyl-D-glycopyranosides of glucose, galactose and mannose were syn thesised from appropriate O-glycosyltrichloroacetimidates and N-(7-hydroxy- 2-oxo-2H-1-benzopyran-3-yl)benzamides in boiling methylene chloride in the presence of boron trifluoride etherate. Heating of these products in a mixt ure of triethylamine and methanol gave the corresponding deprotected 3-benz oylamino-2-oxo-2H-1-benzopyran-7-yl beta-D-glycopyranosides. (C) 2000 Elsev ier Science Ltd. All rights reserved.