Carbamate → HCID 57116212, compound

Participants

Reaction Steps

Lithium borohydride (1.57 g, 73 mmol) was added portionwise to a solution of (2S,4R)-N-(benzoxycarbonyl)-2-methyoxycarbonyl-4-hydroxyproline (46) (20.17 g, 73 mmol) in THF (350 mL) at 0° C. The reaction mixture was allowed to warm to room temperature and stir overnight. The resulting suspension was cooled to 0° C. and quenched with water (2-3 mL) until effervescence ceased, at which point 2 M HCl (15 mL) was added to dissolve the precipitate. The product was extracted with ethyl acetate (3×150 mL) and the combined organic phases washed with brine (1×100 mL) and then dried (MgSO4). Concentration in vacuo afforded a white gum (18.25 g, 100%). [α]22.3D=−404° (C=0.043, CHCl3). 1H NMR (CDCl3): δ1.24-1.26 (m, 1H, H1), 1.73-2.08 (m, 1H, H1), 3.40-4.30 (m, 6H, H2, H3, H11, H11a), 5.06 (bs, 1H, OH), 5.09 (s, 2H, H6) 7.25-7.31 (m, 5H, H arom). 13C NMR (CDCl3): δ36.7 (C1), 55.2 (C3), 58.7 (C2), 65.0 (C11), 67.0 (C6), 68.7 (C11a), 127.0, 127.5 (C arom), 127.8 (C arom), 128.2 (C arom). IR (thin film): ν=3390 (OH), 3065, 3033, 2953 (OH), 1681 (C═O carbamate), 1586, 1538, 1498, 1454, 1192, 1122, 978, 914, 862, 770, 698, 673 cm−1. MS (FAB) m/z (relative intensity): 252 (M+., 58), 208 (33), 176 (5), 144 (6), 118 (8), 116 (7), 92 (13), 91 (100). HRMS calcd. for C13H17NO4=251.1158 found 251.1230.

Provenance & Evidence