Total synthesis of methyl protodioscin: A potent agent with antitumor activity

Methyl protodioscin (1), otherwise known as 3-O-[alpha-L-rhamnopyranosyl-(1-->2)-{alpha-L-rhamnopyranosyl-(1-->4) }-beta-D-glucopyranosyl]-26-O-[beta-D-glucopyranosyl]-22-methoxy-25(R)-furost-5-ene-3beta,26-diol, has been synthesized for the first time from diosgenin through nine steps in an overall yield of 7.8%.