tert-Butyl((E)-3-((E)-2-((1R,3aS,7aR)-1-((2R,5R,e)-5,6-dimethylhept-3-en-2-yl)-7a-methyldihydro-1H-inden-4(2H,5H,6H,7H,7ah)-ylidene)ethylidene)-4-methylenecyclohexyloxy)dimethylsilane