反应详情

3-Methyl 2-(phenylmethyl) (3S)-6,10-dioxa-2-azaspiro[4.5]decane-2,3-dicarboxylate (Intermediate 24) (1.02 g, yield 84%) was prepared from 2-methyl 1-(phenylmethyl) (2S)-4-oxo-1,2-pyrrolidinedicarboxylate (1.0 g, 3.61 mmol) and 1,3-propanediol (0.55 g, 7.21 mmol) following the similar procedure outlined in the preparation of Intermediate 14 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 7.05-7.61 (m, 5H) 4.91-5.25 (m, 2H) 4.29-4.68 (m, 1H) 3.75-4.07 (m, 5H) 3.38-3.75 (m, 4H) 2.25-2.67 (m, 2H) 1.51-2.00 (m, 1H). ES LC-MS m/z=336.6 (M+H)+.