Showing structure for methyl (2s,4r,4ar,6ar,9s,10r,10ar,10br)-9-(acetyloxy)-2-(furan-3-yl)-4,10-dihydroxy-6a,10b-dimethyl-1h,2h,4h,4ah,5h,6h,9h,10h,10ah-naphtho[2,1-c]pyran-7-carboxylate