(((2S,3aS,5aS,9aS,9bS)-5a,9b-dimethyldecahydro-2H-spiro[naphtho[2,1-b]furan-6,2'-[1,3]dioxolan]-2-yl)ethynyl)trimethylsilane

(4aS,5S,8aS)-2,5,8a-Trimethyl-5-(4-methyl-pent-3-enyl)-octahydro-naphthalen-1-one