An expedient synthesis of benzyl 2,3,4-tri-O-benzyl-β-D glucopyranoside and benzyl 2,3,4-tri-O-benzyl-β-D-mannopyranoside

An efficient three-step synthesis of benzyl 2,3,4-tri-O-benzyl-beta-D-glucopyranoside, a widely used building block in carbohydrate chemistry, is described. The key step is the selective debenzylation-acetylation of perbenzylated beta-glucose using ZnCl2-Ac2O-HOAc. This approach was also used to affect an efficient three-step synthesis of benzyl 2,3,4-tri-O-benzyl-beta-D-mannopyranoside. (c) 2005 Elsevier Ltd. All rights reserved.