(Diethylamino)sulfur trifluoride → Tert-butyl 8-but-2-ynyl-10-(fluoromethyl)-11-oxa-3,8-diazaspiro[5.5]undecane-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of diethylaminosulfur trifluoride (19.5 μL, 0.148 mmol) in dichloromethane (1.0 mL) at −78° C. was added dropwise a solution of tert-butyl 8-but-2-ynyl-10-(hydroxymethyl)-11-oxa-3,8-diazaspiro[5.5]undecane-3-carboxylate (50.0 mg, 0.148 mmol) in dichloromethane (1 mL). The reaction was stirred for 10 min at −78° C. then allowed to warm to room temperature and stirred for 16 h. Silica gel chromatography (4 g silica, 0-15% methanol/dichloromethane) provided tert-butyl 8-but-2-ynyl-10-(fluoromethyl)-11-oxa-3,8-diazaspiro[5.5]undecane-3-carboxylate (23.0 mg, 46%). ESI-MS m/z calc. 340.2. found 341.3 (M+1)+; Retention time: 1.16 minutes (3 min run). 1H NMR (400 MHz, CDCl3) δ 4.52-4.40 (m, 1H), 4.39-4.28 (m, 1H), 4.06-3.91 (m, 1H), 3.71 (br s, 2H), 3.35-3.14 (m, 3H), 3.08 (t, J=11.4 Hz, 1H), 2.78 (d, J=10.3 Hz, 1H), 2.58 (d, J=11.1 Hz, 1H), 2.31 (d, J=13.5 Hz, 1H), 2.06 (t, J=12.5 Hz, 2H), 1.84 (t, J=2.3 Hz, 3H), 1.57-1.44 (m, 12H).

Provenance & Evidence