Indeno[4',5':5,6]cyclohepta[1,2-b:3,4-b']- bisoxirene-3a(1H)-carboxylic acid,dodecahydro-5a,7a-dimethyl-3-(1- methylethyl)-,(3R,3aS,5aS,6aR,7aR,7bS,8aS,- 8bS,8cS)-