Imidazole → HCID 15454935, compound

Participants

Reaction Steps

To a stirred and ice-cooled solution of crude (2R*,3S*,4S*,5S*)-1-benzyloxycarbonyl-4-benzyloxymethyl-5-hydroxymethyl-3-methoxycarbonyl-2-phenylpyrrolidine (15.9 g, ca.29.0 mmol) and imidazole (Im, 7.90 g, 116 mmol) in DMF (32.0 ml) was added t-butyldimethylsilyl chloride (8.74 g, 58.0 mmol)in one portion. The cooling bath was removed immediately after the addition, and the stirring was continued at room temperature for ca.5 hours. The reaction mixture was diluted with PhMe--AcOEt (2:1, 300 ml), washed with H2O (×3), and sat. NaCl aq. solution (×2), dried (MgSO4), and concentrated in vacuo to give a colorless oil (20.5 g). This was chromatographed over SiO2 (Merck Kieselgel 60, 200 g). Elution with n-hexane-AcOEt (50:1→20:1→15:1) gave title compound (16.8 g, 96%) as a colorless viscous oil: IR νmax (film): 1743(s), 1705(vs), 1495(m), 1100(s), 780(s), 745(s), 737(s), 700(s) cm-1 ; 1H-NMR δ: 7.48-7.37(m, 3H), 7.37-7.14(m, 11H), 6.90(br.s, 1H), 5.27(br.d,J=6.1 Hz, 1H), 5.02(br.s, 2H), 4.51-4.41(m, 1H), 4.47(s, 2H), 3.97(dd, J=10.3, 2.6 Hz, 1H), 3.94-3.83(m, 1H), 3.60(d, J=3.7 Hz, 2H), 3.54(dd, J=11.8, 9.5 Hz, 1H), 3.33-3.15(m,1H), 3.28(s, 3H), 0.90(br.s, 9H), 0.05(br.s, 6H) ppm.

Provenance & Evidence