4'-Acetyl-3,4-dihydroxy-2-methylenebutanoic acid 2,3,3a,4,5,8,9,11a-octahydro-10-(hydroxymethyl)-6-methyl-3-methylene-2-oxocyclodeca[b]furan-4-yl ester 4-Acetylcnicin AIDS-104628 AIDS104628