2,4-Ethano-4H-indeno[5,6-c]oxeto[3,2-b]furan-8-ol,decahydro-2a,4,5a-trimethyl-8-(1-methylethyl)-,(2R,2aR,4S,4aR,5aR,8R,8aR,9aS)-rel-(+)- (9CI)