(3R,4S,6S,6aR,8R,9S,11aS,11bS)-6-Hydroxy-4-(hydroxymethyl)-4,11b-dimethyldodecahydrospiro[6a,9-methanocyclohepta[a]naphthalene-8,2'-oxiran]-3-yl acetate AIDS-155563 AIDS155563