2H,12H-6,12a-Epoxy-2,7a-methanoindolo(2,3-a)quinolizine-14-carboxylic acid, 3-ethylidene-1,3,4,6,7,12b-hexahydro-9,10-dimethoxy-, methyl ester, (2R,3E,6S,7aR,12aR,12bS,14R)- 74991-69-8