(4'S,4'aS,7'S,8'S,8'aS)-7'-Methoxymethoxy-4'a,8'-dimethyl-octahydro-spiro[[1,3]dioxolane-2,2'-naphthalene]-4'-carboxylic acid

(4'S,4'aS,7'S,8'S,8'aS)-7'-Methoxymethoxy-4'a,8'-dimethyl-octahydro-spiro[[1,3]dioxolane-2,2'-naphthalene]-4'-carboxylic acid methyl ester