Acetic Acid → HCID 15454938, compound

Participants

Reaction Steps

To a stirred and ice-cooled solution of (2S*,3S*,4S*,5S*)-1-benzyloxycarbonyl-4-benzyloxymethyl-3-[N-(t-butoxycarbonyl)amino]-5-(t-butyldimethylsilyloxy)methyl-2-phenylpyrrolidine (14.5 g, ca.21.3 mmol) in dry THF (20 ml) was added a mixture of glacial AcOH (1.59 ml, d1.049, 27.7 mmol) and a 1.0M solution of (n-Bu)4NF in THF (Aldrich, 32.0 ml, 32.0 mmol) dropwise. After stirring at room temperature for 6 hours, a further amount of a 1.0M solution of (n-Bu)4NF in THF (15.0 ml, 15.0 mmol) was added dropwise at room temperature. After the stirring was continued for 2 days, the resultant orange mixture was neutralized with sat. NaHCO3 aq. solution, and concentrated in vacuo at a bath temperature of 40 C. The residue was diluted with AcOEt (200 ml), washed with H2O (×2), sat. NaHCO3 aq. solution (×1), and sat. NaCl aq. solution (×1), dried (MgSO4), and concentrated in vacuo to give a dark red viscous oil (13.9 g). This was chromatographed over SiO2 (Merck Kieselgel 60, 130 g). Elution with n-hexane-AcOEt (20:1→10:1→5:1→4:1→2:1) gave a red solid (10.6 g). This was recrystallized from AcOEt-n-hexane; the crystals were filtered off, washed with AcOEt-n-hexane (1:4, ×1), and dried in vacuo to give the title compound (9.0 g, 78%) as a slightly purple crystals. A portion of it was recrystallized from AcOEt-n-hexane to afford an analytical sample of the title compound: mp 126.5-129.5 C. (white fine needles); IRmax (nujol): 3430(s), 3380(s), 1690(vs), 1518(s), 1498(m), 1100(s), 785(m), 770(s), 747(s), 740(s), 715(s), 695(s) cm-1 ; 1H-NMR δ: 7.45-7.15(m, 17H), 6.94(br.s, 1H), 5.22(d, J=8.1 Hz, 1H), 5.02(br.s, 2H), 4.87(br.s, 1H) 4.52(s), 2H), 4.30(dd, J=19.0, 9.0 Hz, 1H), 4.2-4.00(m, 2H), 4.03-3.90(m, 1H), 3.68-3.50(m, 2H), 2.10-1.85(m, 1H), 1.37(br.s, 9H) ppm.

Provenance & Evidence