Potassium bisulfate → tert-butyl (2S)-2-(hydroxymethyl)azetidine-1-carboxylate

Participants

Reaction Steps

To an ice-cooled solution of the compound of step 7a (9.39 g, 46.72 mmol) in tetrahydrofuran (100 mL) was added borane/THF complex (1 M, 210 mL, 4.5 eq.) under nitrogen. The reaction was gradually warmed to room temperature and stirred for 48 hours, after which a 10% aqueous potassium hydrogen sulfate solution (60 mL) was added gradually, then the volatiles were evaporated in vacuo. The remaining slurry was diluted with ethyl acetate (100 mL), and triturated two additional times. The organic phase was then washed with a saturated solution of sodium hydrogen carbonate (3×75 mL), dried (MgSO4), filtered and concentrated in vacuo, yielding a colorless oil (8.4 g, 96% yield). This material was carried forward without further purification. MS (DCI/NH3) m/e 188 (M+H)+. 1H NMR (CDCl3, 300 MHz) δ: 4.49-4.40 (ddd, J=9.0 Hz, J=9.0 Hz, J=3.0 Hz, 1H), 3.95-3.68 (m, 4H), 2.23-2.12 (m, 1H), 1.99-1.87 (m, 1H), 1.46 (s, 9H).

Provenance & Evidence