Sodium Carbonate → rac-(4aR*,8aR*)-tert-butyl 2-oxohexahydro-2H-pyrido[4,3-e][1,3]oxazine-7(3H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a mixture of rac-(3R*,4R*)-tert-butyl 4-(aminomethyl)-3-hydroxypiperidine-1-carboxylate (3.39 g, 14.72 mmol; prepared according to Tetrahedron (2008), 64, 2456-2464) in MEK (40 mL) heated to 60° C. was added CDI (3.58 g, 22.08 mmol, 1.5 eq). The mixture was stirred for 3 h. Na2CO3 (5% aq., 4 mL) was added. The reaction proceeded at rt for 70 min. The two layers were decanted and the aq. layer was extracted with EA (10 mL). The combined org. layers were washed with brine (8 mL), dried over Na2SO4, filtered and concentrated to dryness. The residue was purified by CC (DCM to DCM/MeOH 9:1) to afford the title compound as a white solid (2.59 g).

Provenance & Evidence