Aspidospermidine-3-carboxylicacid, 4-(acetyloxy)-6,7-didehydro-15-[(3b,5a,7b,12b,19a)-1,2-didehydro-7-ethyl-7-hydroxy-3-(methoxycarbonyl)-20,21-dinoraspidospermidin-3-yl]-1-formyl-3-hydroxy-16-methoxy-,methyl ester, (2b,3b,4b,5a,12b,19a)-