Allyl Mercaptan → (2S,4R)-1-benzyl 2-methyl 4-(allylthio)-4-(biphenyl-4-yl)pyrrolidine-1,2-dicarboxylate

Participants

Reaction Steps

To a clear solution of (2S,4R)-1-benzyl 2-methyl 4-(biphenyl-4-yl)-4-hydroxypyrrolidine-1,2-dicarboxylate (3236 mg, 7.5 mmol) and prop-2-ene-1-thiol (834 mg, 9.00 mmol) in Acetonitrile (40 mL) was added Scandium(III) trifluoromethanesulfonate (369 mg, 0.750 mmol) as solid by one portion at room temperature. The formed pink solution was stirred at this temperature for 20 h. Quenched with sat. ammonium chloride, extracted with EtOAc. Washed the organic with brine, dried over MgSO4, filtered, and concentrated in vacuo. The residue was purified by Biotage column, eluted with 5%˜50% EtOAc-Hexane to afford a mixture of the diasteromers (2.88 g, 79%) and the starting material (0.600 g, 18%). This mixture of the diasteromers was purified by Biotage column again, eluted with 2%˜8% EtOAc-Toluene to afford the desired product (2S,4R)-1-benzyl 2-methyl 4-(allylthio)-4-(biphenyl-4-yl)pyrrolidine-1,2-dicarboxylate (900 mg, 1.661 mmol, 22.15% yield) as the second peak collected from the column as a viscous oil. 1H NMR (500 MHz, CHLOROFORM-D) δ ppm 2.59-2.76 (m, 1 H) 2.78-2.93 (m, 3 H) 3.60 (s, 1.5 H) 3.77 (s, 1.5 H) 3.92 (d, J=11.60 Hz, 1 H) 4.17-4.31 (m, 1 H) 4.34-4.49 (m, 1 H) 4.92-5.07 (m, 2 H) 5.08-5.34 (m, 2 H) 5.53-5.72 (m, 1 H) 7.23-7.41 (m, 6 H) 7.45 (t, J=7.63 Hz, 3 H) 7.48-7.67 (m, 5 H).

Provenance & Evidence