(6aR,8aS,8bS,10S,11aR)-10-(furan-2-yl)-8b-(2-hydroxyacetyl)-8a-methyl-5,6,6a,6b,7,8,8a,8b,11a,12,12a,12b-dodecahydro-1H-naphtho[2',1':4,5]indeno[1,2-d][1,3]dioxol-4(2H)-one