(1S,2R,5S,8aR)-1,2,3,5,6,7,8,8a-octahydro-1-tert-butyldimethylsilyloxymethyl-2,5-dimethyl-5-(4-methyl-4-pentenyl)-1-[(2-tetrahydro-2-pyranyloxy)ethyl]naphthalene