(+)-Epichlorohydrin → (2S,9S)-2-[(tert-Butoxycarbonyl)amino]-10-chloro-9-hydroxy-7-azadecanoic Acid tert-Butyl Ester

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Reaction Steps

A solution of 3 (4.83 g, 14.3 mmol) in chloroform (100 mL) was extracted with saturated NaHCO3 solution (2×100 mL) and water (100 mL). The organic layer was dried, concentrated, and further dried in vacuo. The resulting oil was dissolved in cyclohexane (26 mL), and (S)-(+)-epichlorohydrin (1.58 g, 17.1 mmol) was added under an Ar atmosphere. The precipitated product was filtered after 27 h, washed with cold cyclohexane, and dried in vacuo to give 12a (2.20 g, 39%) as a fine, white powder: mp 87-88° C.; 1H NMR δ 1.30-1.83 (m, 6H), 1.44 (s, 9H), 1.46 (s, 9H), 2.57-2.66 (m, 3H), 2.77 (dd, 1H, J=12.2, 3.9), 3.51 (dd, 1H, J=11.2, 5.7), 3.56 (dd, 1H, J=11.2, 5.2), 3.84-3.91 (m, 1H), 3.94 (dd, 1H, J=8.6, 5.3); 13C NMR 6 24.6, 28.3, 28.7, 30.0, 32.6, 48.2, 50.3, 53.5, 55.8, 71.1, 80.4, 82.5, 158.1, 173.8; HRMS m/z calcd for C18H36ClN2O5 395.2313, found 395.2303. Anal. calcd. for C18H35ClN2O5: C54.74, H 8.93, Cl 8.98, N 7.09. Found: C 54.80, H. 8.99, Cl 9.02, N 7.08 [α]22D−26.1° (c 1.00, CH3OH).

Provenance & Evidence