General procedure for the synthesis of 4-N-benzyloxycarbonylaminocyclohexanone from benzyl (trans-4-hydroxycyclohexyl)carbamate: synthesis of compound 120.3. Jones reagent (~10 mL) was added slowly and dropwise to a solution of compound 120.2 (7.0 g, 28.08 mmol, 1.00 eq.) in acetone (100 mL) at 0 °C. The reaction process was monitored by thin layer chromatography (TLC). After stirring the reaction mixture for 30 minutes, the reaction was quenched with saturated aqueous sodium bisulfite (NaHSO3) solution. Subsequently, extraction was performed with ethyl acetate (EtOAc, 3 x 100 mL). The organic layers were combined, washed with saturated aqueous sodium chloride (NaCl), dried over anhydrous sodium sulfate (Na2SO4), and finally concentrated under reduced pressure to give 5.0 g (72% yield) of compound 120.3 as a white solid.
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