15α20β-Dihydr­oxy-6β-meth­oxy-67-seco-620-ep­oxy-17-olide-ent-kaur-16-ene

摘要

The title compound, C21H30O6, a natural ent-kaurane diterpenoid, was obtained from the medicinal plant Isodon serra. The five rings in the mol­ecule exhibit the expected cis and trans junctions. The three six-membered rings adopt chair, twist-boat and boat conformations, while two five-membered rings adopt envelope conformations. There are two mol­ecules in the asymmetric unit, related by a non-crystallographic twofold screw axis; the main difference is in the different degrees of distortion of ring B. In the crystal, the mol­ecules are linked by inter­molecular O—H⋯O hydrogen bonds, forming chains along the b axis.