Benzyl chloroformate → 1,2-Dibenzyl 3-(tert-butyl) (2S,3S)-5-methylenepiperidine-1,2,3-tricarboxylate

Participants

Reaction Conditions

Reaction Steps

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)).

Provenance & Evidence