Benzyl chloroformate → 1,2-Dibenzyl 3-(tert-butyl) (2S,3S)-5-methylenepiperidine-1,2,3-tricarboxylate
Reaktionsgleichung
C([N:8]1[CH2:13][C:12](=[CH2:14])[CH2:11][C@H:10]([C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])[C@H:9]1[C:22]([O:24][CH2:25][C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1)=[O:23])C1C=CC=CC=1.Cl[C:33]([O:35][CH2:36][C:37]1[CH:42]=[CH:41][CH:40]=[CH:39][CH:38]=1)=[O:34]>>[CH2:14]=[C:12]1[CH2:13][N:8]([C:33]([O:35][CH2:36][C:37]2[CH:42]=[CH:41][CH:40]=[CH:39][CH:38]=2)=[O:34])[C@H:9]([C:22]([O:24][CH2:25][C:26]2[CH:27]=[CH:28][CH:29]=[CH:30][CH:31]=2)=[O:23])[C@@H:10]([C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])[CH2:11]1Komponenten
3
Reaktionsbedingungen
- Temperatur
- 65 °C
Versuchsvorschrift
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)).