SPIRO[CYCLOPENTANE-1,6'-[6H]CYCLOPROP[B]-ASINDACENE],3'-[(1R)-1,5-DIMETHYLHEXYL]- DODECAHYDRO-3'A,5'B-DIMETHYL-,(3'R,3'AR,- 5'AS,5'BR,6'AR,7'AS,7'BS)-