12,13,20-Tributylate AIDS-159689 AIDS159689 Butanoic acid, [(1aR,1bS,4aS,7aS,7bS,8R,9R,9aS)-1a,1b,4,4a,5,7a,7b,8,9,9a-decahydro-4a,7b-dihydroxy-1,1,6,8-tetramethyl-5-oxo-9,9a-bis(1-oxobutoxy)-1H-cyclopropa[3,4]benz[1,2-e]azulen-3-yl]methyl ester