3H,8H-Furo(2',3',4':4,5)oxireno(7,8)naphtho(2,1-c)pyran-3,8-dione,1a,2,2a,4a,4b,6,9b,9c-octahydro-2-hydroxy-2a,9b-dimethyl-, (1aR,2R,2aR,4aR,4bR,9bS,9cS)- 76235-83-1