反应详情

To (2S)-4-oxo-piperidine-1,2-dicarboxylic acid 1-tert-butyl ester (0.52 g, 2.15 mmol) in methanol (10 mL), 2 M solution of TMS-diazomethane (2 mL, 4 mmol) in hexane was added and stirred at room temperature for 15 min. The reaction solvent was removed and the methyl ester product obtained (4-oxo-piperidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester) was used as such for the next reaction (0.55 g, 100%): MS (ESPOS): 258 [M+H]+; 1H NMR (300 MHz, CD3OD) δ 5.13, 4.86 (bs, 1), 4.02–4.11 (m, 1), 3.73 (s, 3), 3.67–3.72 (m, 1), 2.78 (d, J=4.2 Hz, 2), 2.51 (bs, 2), 1.46 (bs, 9).

1. customThe reaction solvent was removed