9-(acetoxymethyl)-7-cyano-6,7,9,14,14a,15-hexahydro-2,11-dimethoxy-3,12,16-trimethyl-(6S,7R,9R,14aS,15R)-(-)-6,15-imino-4H-isoquino[3,2-b][3]benzazocine-1,4,10,13(5H)-tetrone