2-Butenoic acid, 2-methyl-4-[(4S,4aS,5S,8S,8aS)-4,4a,5,6,7,8,8a,9-octahydro-8-hydroxy-3,4a,5-trimethyl-9-oxonaphtho[2,3-b]furan-4-yl]-, (2E)- AIDS-221751 AIDS221751