Tert-butyl 6-oxa-7-azabicyclo[3.2.2]non-8-ene-7-carboxylate → tert-butyl N-[(1S,4R)-4-hydroxycycloheptyl]carbamate

Participants

Reaction Steps

A Parr bottle was charged with Raney Nickel (ca. 1 g). The catalyst was washed with ethanol and suspended in ethanol (30 mL). The starting material, 23A (1.0 g, 4.44 mmol) was added and the reaction pressurized with hydrogen. After hours, TLC analysis suggests good conversion to desired product. The reaction was flushed with nitrogen and filtered through a pad of magnesium sulfate. The filter cake was rinsed well with ethanol. The ethanol solution was evaporated. The isolated material was dissolved in tetrahydrofuran to give a cloudy solution. The liquid was passed through a PTFE filter and then evaporated. The crude product was crystallized from ether-hexanes. The crystalline material was filtered off and rinsed with hexanes. Residual solvent was removed under vacuum to give 23B (780 mg, 3.40 mmol, 77% yield) as a colorless solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 6.76 (d, 1H, J=7.6 Hz); 4.36 (d, 1H, J=4.0 Hz); 3.51-3.73 (m, 1H); 3.37 (br. s, 1H); 1.69-1.91 (m, 2H); 1.45-1.66 (m, 5H); 1.37 (s, 9H); 1.06-1.34 (m, 3H).

Provenance & Evidence