Synthesis of the ABC skeleton of the aglycon of Echinoside A

Echinoside A is a triterpene saponin isolated from the sea cucumber Actinopyga echinites (JAEGER), which displays potent antitumor activities in vitro and in vivo. Here, we report the synthesis of the ABC-fused ring skeleton of the aglycon of Echinoside A, with the enantiomerically pure (+)-Wieland–Miescher ketone being used as starting material and a Robinson annulation as the key reaction.

Graphical abstractWe report the synthesis of the ABC-fused ring skeleton of the aglycon of Echinoside A, with the enantiomerically pure (+)-Wieland–Miescher ketone being used as starting material and a Robinson annulation as the key reaction.Figure optionsDownload full-size imageDownload as PowerPoint slide