2H,6H-1,4,5-Trioxadicyclopent(a,hi)indene-7-carboxylic acid, 3-ethylidene-3,3a,4a,7,7a,9b-hexahydro-6-hydroxy-2-oxo-, methyl ester, (3E,3aalpha,4abeta,6beta,7alpha,7abeta,9aR*,9bbeta)- 51820-82-7 Allamandin NSC 251690