Exhaustive degradation of the ring D of 3,20-epoxy ent-kaurane-type diterpene maoecrystal A

This study described a new approach for exhaustive degradation of the ring D of maoecrystal (), an ent-kaurane-type diterpene from Isodon eriocalyx, in seven steps mainly involving retro-aldol reaction, epoxylation, NaIO4 oxidation, and Baeyer–Villiger process in a 19% overall yield.