An improved synthesis of the saponin, polyphyllin D Original Research Article

Polyphyllin D, namely diosgenyl α-l-rhamnopyranosyl-(1→2)-[(α-l-arabinofuranosyl)-(1→4)]-β-d-glucopyranoside, was synthesized from diosgenyl-β-d-glucopyranoside in four steps and in 30% overall yield, taking advantage of regioselective pivaloylation and α-l-rhamnopyranosylation reactions.