TOTAL SYNTHESIS OF THE PHENYLPROPANOID GLYCOSIDE, GRAYANOSIDE-A

Grayanoside A, 2-(4-hydroxyphenyl)ethyl 6-O-feruloyl-beta-D-glucopyran oside, was synthesized for the first time by using chloroacetyl groups for the protection of hydroxy functions. 2-(4-Allyloxyphenyl)ethyl l] -2,3,6-tri-O-chloroacetyl-beta-D-glucopyranoside (12) was synthesized from 2-(4-allyloxyphenyl)ethyl 4,6-O-benzylidene-beta-D-glucopyranosid e (8) in four steps with the goal of preparing syringalide B. It was f ound, however, that the feruloyl group migrated from the 4- to the 6-p osition of the glycopyranoside during the deprotection of 12. (C) 1997 Elsevier Science Ltd.