反应详情

SOCl2 (2.5 eq) was added at 0° C. to a 0.2M solution of (3R,7aR)-7a-[(benzyloxy)methyl]-3-(trichloromethyl)tetrahydro-1H-pyrrolo[1,2-c][1,3]oxazol-1-one in dry MeOH, and the mixture was stirred at RT for 20 min, then at reflux for 4 h. After removal of volatiles the residue was taken in EtOAc and washed with sat NaHCO3, water and brine, dried and concentrated. A 0.2M solution in dry Et2O of crude methyl 2-[(benzyloxy)methyl]-L-prolinate was added at 0° C. to a stirred mixture of LiBH4 (1.6 eq.) and MeOH (1.6 eq.) in dry Et2O (0.3M); the mixture was stirred for 2 h at RT, then quenched with water, diluted with EtOAc, washed with water and brine, dried and concentrated to afford {(2S)-2-[(benzyloxy)methyl]pyrrolidin-2-yl}methanol that was used as such. The material was dissolved in dry DCM (0.2M) and treated with carbonyl diimidazol (2.5 eq.) at RT overnight; after dilution with DCM the mixture was washed with 1N HCl, sat NaHCO3 and brine, dried over Na2SO4 and concentrated. Flash chromatography (PE:EtOAc 2:1) afforded the title compound in 43% overall yield.

1. temperatureat reflux for 4 h
2. customAfter removal of volatiles the residue
3. washwashed
4. customdried
5. concentrationconcentrated
6. stirringthe mixture was stirred for 2 h at RT
7. customquenched with water
8. additiondiluted with EtOAc
9. washwashed with water and brine
10. customdried
11. concentrationconcentrated