tert-butyl (2S)-2-formylpyrrolidine-1-carboxylate → BOC-2(S)-(cyclopentanecarbonyl)pyrrolidine
Reaction equation
[CH:1]1([Mg]Cl)[CH2:5][CH2:4][CH2:3][CH2:2]1.[C:8]([N:15]1[CH2:21][CH2:20][CH2:19][C@H:16]1[CH:17]=[O:18])([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9]>>[C:8]([N:15]1[CH2:21][CH2:20][CH2:19][C@H:16]1[C:17]([CH:1]1[CH2:5][CH2:4][CH2:3][CH2:2]1)=[O:18])([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9]Participants
3
Procedure
22.5 ml (45 mmol) 2 M cyclopentylmagnesium chloride (diethyl ether) and 3.0 g (15 mmol) BOC-L-prolinal were allowed to react at −80° C. for 30 min according to procedure F. Yield of crude product 3.37 g. The product was purified with a silica column using 0–4% methanol in dichloromethane as eluent. Yield 3.10 g (11.5 mmol, 77%). The product was oxidized to the corresponding ketone according to procedure G. Yield of crude product 3.12 g. The product was purified with a silica column using 16% ethyl acetate in petroleum ether as eluent. Yield 1.3 g (4.9 mmol, 42%).
Workup
- customto react at −80° C. for 30 min
- customThe product was purified with a silica column