Hydrochloric Acid → (3R,4S)-3-acetamido-N-tert-butyl-4-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)propyl]pyrrolidine-3-carboxamide hydrochloride

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Reaction Steps

While under nitrogen, a stirred solution of tert-butyl (3R,4S)-3-acetamido-3-(tert-butylcarbamoyl)-4-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)propyl]pyrrolidine-1-carboxylate (400 mg, 0.807 mmol) in anhydrous THF (5 mL) was treated with 4 M HCl in 1,4-dioxane (3.03 mL, 12.1 mmol). After 2.5 h, the mixture was diluted with diethyl ether (15 mL) and filtered, washed with additional ether and concentrated to give (3R,4S)-3acetamido-N-tert-butyl-4-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)propyl]pyrrolidine-3-carboxamide hydrochloride (340 mg, 97%) as a white solid. 1H NMR (D2O, 400 MHz) δ 4.11 (d, J=12 Hz, 1 H), 3.58 (dd, J=11.5, 7.7 Hz, 1 H), 3.19 (d, J=12 Hz, 1 H), 3.01 (t, J=11.5, 1 H), 2.42 (m, 1 H), 1.92 (s, 3 H), 1.52 (m, 1 H), 1.30 (m, 2 H), 1.19 (s, 9 H), 1.16 (s, 12 H), 1.08 (m, 1 H), 0.75 (m, 2 H). LC-MS gives ESI+ MS found for C20H38BN3O4 m/z 396.1 (M+H).

Provenance & Evidence