Lithium Hydroxide → (2S,5R)-6-(Benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]octane-2-carboxylic acid

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Reaction Steps

LiOH (1.2 g, 29.6 mmol) was added to a solution of (2S,5R)-ethyl 6-(benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]octane-2-carboxylate (9 g, 29.6 mmol) in THF/H2O (3:1, 240 mL). The mixture was then stirred at rt overnight. The reaction mixture was washed with EtOAc twice, then the aqueous solution was adjusted pH 2-3 with 1N HCl. The resulting mixture was extracted with DCM three times, and the combined organic layer was dried over saturated Na2SO4 and concentrated in vacuum to provide (2S,5R)-6-(benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]octane-2-carboxylic acid (7.0 g, 77.7%), which was directly used in the next step without further purification. ESI-MS (EI+, m/z): 277.31. 1H NMR (300 MHz, CDCl3) δ 7.49-7.29 (m, 5H), 5.06 (d, J=11.4 Hz, 1H), 4.91 (d, J=11.4 Hz, 1H), 4.15-4.10 (m, 1H), 3.36-3.34 (m, 1H), 3.15-3.11 (m, 1H), 2.83 (d, J=11.8 Hz, 1H), 2.32-2.15 (m, 1H), 2.11-2.01 (m, 2H), 1.74-1.56 (m, 1H).

Provenance & Evidence