5,8,8a,9,10,11,12,12a,13,13a-decahydro-3-methoxy-12-(methylsulfonyl)-6H-isoquino(2,1-g)(1,6)naphthyridine, (8aR-(8aalpha,12aalpha,13aalpha))-isomer
5,8,8a,9,10,11,12,12a,13,13a-decahydro-3-methoxy-12-(methylsulfonyl)-6h-isoquino(2,1-g)(1,6)naphthyridine, (8ar-(8aalpha,12aalpha,13aalpha))-isomer