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, 111), 1.46 (s, 9H).

Provenance & Evidence