2-Butenoic acid, 2-methyl-, 1,3,3a,4,14,14a-hexahydro-6,7,8-trimethoxy-3-oxobenzo(3,4)furo(3',4':6,7)cycloocta(1,2-f)(1,3)benzodioxol-14-yl ester, stereoisomer 41451-69-8 BRN 4730154 Steganangin