反应详情

To a clear solution of (2S,4R)-1-benzyl 2-methyl 4-(biphenyl-4-yl)-4-hydroxypyrrolidine-1,2-dicarboxylate (2.59 g, 6 mmol) and 1-butanethiol (0.773 mL, 7.20 mmol) in acetonitrile (30 mL) was added Scandium(III) trifluoromethanesulfonate (0.295 g, 0.600 mmol) as solid by one portion at room temperature. The formed pink solution was stirred at this temperature for 26 h. TLC analysis showed starting material was completely consumed. Quenched with sat. ammonium chloride, extracted with EtOAc. Washed the organic with brine, dried over MgSO4, filtered, evaporated in vacuo. The residue was purified by BIOTAGE® column, eluted with gradient 5˜40% EtOAc-hexane to afford the mixture of diastereomers 2.54 g (84%). This oily mixture was purified by BIOTAGE® again, eluted with gradient 0˜20% EtOAc-toluene. The first peak collected from the column afforded by-product (2S,4S)-1-benzyl 2-methyl 4-(biphenyl-4-yl)-4-(butylthio)pyrrolidine-1,2-dicarboxylate (1.54 g, 2.60 mmol, 43.3% yield) as a wax. 1H NMR (500 MHz, CHLOROFORM-d) ppm 0.77 (t, J=7.17, 3H), 1.21-1.24 (m, 2H), 1.28-1.34 (m, 2H), 2.20-2.29 (m, 2H), 2.41-2.46 (m, 1H), 2.86 (dd, J=12.82, 7.32 Hz, 1H), 3.53, 3.75 (s, rotomer, 3H), 3.89 (dd, J=17.09, 11.29 Hz, 1H), 4.23-4.36 (m, 1H), 4.69-4.77 (m, 1H) 5.22-5.30 (m, 2H) 7.28-7.44 (m, 10H), 7.53-7.60 (m, 4H). LC-MS (retention time: 3.28 min, method B), MS m/z 504 (M+H).

1. customwas completely consumed
2. customQuenched with sat. ammonium chloride
3. extractionextracted with EtOAc
4. washWashed the organic with brine
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. customevaporated in vacuo
8. customThe residue was purified by BIOTAGE® column
9. washeluted with gradient 5˜40% EtOAc-hexane
10. customto afford
11. additionthe mixture of diastereomers 2.54 g (84%)
12. customThis oily mixture was purified by BIOTAGE® again
13. washeluted with gradient 0˜20% EtOAc-toluene
14. customThe first peak collected from the column