Benzaldehyde → tert-butyl (4aS*,5R*,10bS*)-5-phenyl-3,4,4a,5,6,10b-hexahydrobenzo[h]-1,6-naphthyridine-1(2H)-carboxylate

Participants

Reaction Steps

Benzaldehyde (531 mg, 5 mmol) was dissolved in acetonitrile (15 ml), aniline (466 mg, 5 mmol) was added at 0° C., and the mixture was stirred at the same temperature for 1 hr. tert-Butyl 3,4-dihydropyridine-1(2H)-carboxylate (917 mg, 5 mmol) and Dy(OTf)3 (153 mg, 0.25 mmol) were added at 0° C., and the mixture was further stirred for 1.5 hrs. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The extract was washed with 6% aqueous sodium hydrogen carbonate solution and saturated brine and dried (over anhydrous MgSO4), and the solvent was evaporated under reduced pressure. The residue was subjected to column chromatography using silica gel (100 g), and eluted with hexane-ethyl acetate (19:1-6:1, v/v). The title compound (4aR*,5R*,10bR*) (109 mg, 6%) was obtained as a colorless amorphous form from the first eluted fraction.

Provenance & Evidence