Synthesis of bidesmosidic dihydrodiosgenin saponins bearing a 3-O-β-chacotriosyl moiety Original Research Article

3-O-β-Chacotriosyl-26-O-β-d-glucopyranosyl-(25R)-furost-5-en (1), a mimic of the antitumor active proto-dioscin, was concisely synthesized from diosgenin in a linear nine steps and in 17% overall yield. Its congeners with a α-l-rhamnopyranosyl, β-lactosyl, or without a substituent at the 26-OH (13–15) were also prepared. Compound 1, as well as 13–15, did not show any inhibition against tumor cells, implying that proto-dioscin might be also inactive, but readily converted into the antitumor active dioscin.