1856-57-1 40285-97-0 Dihydroalantolactone Naphtho(2,3-b)furan-2(3H)-one, 3a,5,6,7,8,8a,9,9a-octahydro-3,5,8a-trimethyl-, (3S-(3alpha,3abeta,5alpha,8aalpha,9abeta))-