反应详情

温度

65 °C

A mixture of 2-benzyl 3-tert-butyl(2S,3S)-1-benzyl-5-methylenepiperidine-2,3-dicarboxylate from step 1d (2.3 g) and benzyl chloroformate (3 mL) was stirred at 65° C. for 28 h. The excess of the benzyl chloroformate was removed under reduced pressure. The residue was purified through Combiflash (hexane and ethyl acetate: gradient 0 to 10% during 12 min) to give the desired compound 1,2-dibenzyl 3-tert-butyl(2S,3S)-5-methylenepiperidine-1,2,3-tricarboxylate (1.40 g). MS (ESI): 488.1 (M+Na+); 366.1 (M+H+—COO(t-Bu)).

1. customThe excess of the benzyl chloroformate was removed under reduced pressure
2. customThe residue was purified through Combiflash (hexane and ethyl acetate: gradient 0 to 10% during 12 min)