The synthesis of gracillin and dioscin: two typical representatives of spirostanol glycosides Original Research Article

Two representative spirostanol saponins that have the typical structure for the sugar moiety, diosgenyl α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→3)]-β-d-glucopyranoside (gracillin) and diosgenyl α-l-rhamnopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→4)]-β-d-glucopyranoside (dioscin), were easily synthesized by a general approach. A procedure using guanidine for the selective deblocking of acetyl while retaining benzoyl protecting groups is described.