2-Butenoic acid, 2-methyl-, 2,3,3a,4,4a,5,7a,8,9,9a-decahydro-4a,8-dimethyl-3-methylene-2,5,9-trioxoazuleno[6,5-b]furan-4-yl ester, (3a.alpha.,4.alpha.,4a.beta.,7a.alpha.,8.alpha.,9a.alpha.)- MULTISTATIN NSC280414