Rd. Clark et al., STEREOSPECIFIC SYNTHESIS OF THE -ALPHA)-DECAHYDROBENZO[A]PYRROLO[3,2-G]QUINOLIZINE RING-SYSTEM, Journal of heterocyclic chemistry, 30(3), 1993, pp. 829-831
A stereospecific synthesis of racemic thylsulfonyl)benzo[alpha]pyrrolo
[3,2-g]quinolizine (2) is reported. Cyclocondensation of lithiated pyr
rolecarboxamide 5 and dihydroisoquinoline 6 afforded the key tetracycl
ic intermediate 7. Hydrogenation of 7 gave the 3aalpha 11balpha, 12aal
pha-isomer 9 which was subsequently converted to 2.