Water → HCID 15454949, compound

Participants

Reaction Steps

To a stirred and water-cooled solution of (2S*,3S*,4R*,5R*)-1-benzyloxycarbonyl-3-[N-(t-butoxycarbonyl)amino]-4-hydroxymethyl-5-methyl-2-phenylpyrrolidine (2.60 g, 5.90 mmol) and Et3N (5.70 ml, d0.726, 40.9 mmol) in DMSO (dried over molecular sieves 4, 36 ml) was added sulfer trioxide pyridine complex (SO3Py, Wako, 5.42 g, 34.1 mmol) portionwise. Just after the addition the water bath was removed, and the stirring was continued at room temperature for 1.5 hours. The reaction mixture was poured into a mixture of ice and water (80 ml). The mixture was extracted with CH2Cl2 (30 ml×5). The combined CH2Cl2 extracts were washed with 10% citric acid aq. solution (30 ml×4) until the aqueous washing reached the acidity of citric acid (pH ca.3), H2O (30 ml×1), sat. NaHCO3 aq. solution (40 ml×1), and sat. NaCl aq. solution (×1), dried (MgSO4), and concentrated in vacuo to give crude title compound (3.66 g, quant.) as a pale yellow viscous oil; while the yield was overestimated owing to contamination with the solvent employed, this crude product solidified on standing in a refrigerator: IRmax (film): 3400(m, shoulder), 3350(m), 2720(w), 1710(vs), 1690(vs, shoulder), 1605(w), 1585(w), 1520(s), 1500(s), 1165(s), 770(m), 730(s), 700(s) cm-1 ; 1H-NMR δ: 9.65(d, J=3.7 Hz, 1H), 7.40-7.10(m, 9H), 7.05(br.s, 1H), 5.27(d, J=8.5 Hz, 1H), 5.06(br.s, 2H), 4.78-4.57(m, 1H), 4.24(dq, J=9.5, 6.1 Hz, 1H), 4.05(br.d, J=9.2 Hz, 1H), 2.77-2.50(m, 1H), 1.61(d, J=6.1 Hz, 1H), 1.37(s, 9H) ppm. This was employed in the next step without further purification.

Provenance & Evidence