Synthesis of a New Phenol Glycoside, Neohancoside C from Cynanchum hancockianum.

Neohancoside C (1) is a new phenol glycoside isolated from Cynanchum hancockianum, which is a Chinese folk medicine having antitumor activity. The synthesis of 1, 2-acetylphenyl β-D-xylopyranosyl-(1→6)-β-D-glucopyranoside, was achieved by phase-transfer-catalyzed glycosidation using glycosyl bromide.