反应详情

Utilizing Method B, (R)—N-(4-azidobenzyl)-2-acetamido-3-hydroxypropanamide (1.16 g, 4.19 mmol), Ag2O (4.85 g, 20.94 mmol), and MeI (2.61 mL, 41.89 mmol) gave crude (R)-5 after 4 d. The product was purified by column chromatography (SiO2; 1/9 MeOH/CHCl3) to obtain 0.98 g (80%) of (R)-5 as a white solid: mp 149-150° C.; [α]26D −15.2° (c 1.0, MeOH); Rf=0.5 (1/9 MeOH/CHCl3); IR (nujol mull) 3285, 2931, 2113, 1635, 1560, 1456 cm−1; 1H NMR (CDCl3) δ 2.03 (s, CH3C(O)), 3.38 (s, OCH3), 3.44 (dd, J=7.5, 9.3 Hz, CHH′OCH3), 3.80 (dd, J=4.2, 9.3 Hz, CHH′OCH3), 4.40 (½HH′q, J=6.2, 15.0 Hz, CHH′Ar), 4.46 (½HH′q, J=6.2, 15.0 Hz, CHH′Ar), 4.52-4.58 (m, CH), 6.48 (br d, J=6.3 Hz, NHCH), 6.82-6.85 (br m, NHCH2), 6.96-7.01 (m, 2 ArH), 7.23-7.28 (m, 2 ArH), addition of excess (R)-(−)-mandelic acid to a CDCl3 solution of (R)-5 gave only a single signal for the acetyl methyl protons and the ether methyl protons, addition of excess (R)-(−)-mandelic acid to a CDCl3 solution of (R)-5 and (S)-5 (1:2 ratio) gave two signals for the acetyl methyl protons (δ 1.995 (R) and 2.010 (S) (Δppm=0.015)), and two signals for the ether methyl protons (δ 3.302 (S) and 3.342 (R) (Δppm=0.040)); 13C NMR (CDCl3) δ 23.4 (CH3C(O)), 43.1 (CH2Ph), 52.7 (CH), 59.3 (CH2OCH3), 71.8 (CH2OCH3), 119.5, 129.1, 134.9, 139.5 (C6H5), 170.2, 170.5 (2C(O)); HRMS (ESI) 292.1406 [M+H+] (calcd. for C13H18N5O3 292.1410); Anal. (C13H17N5O3) Calcd.: C, 53.60%; H, 5.88%; N, 24.04%. Found: C, 53.72%; H, 5.91%; N, 23.84%.

1. customgave crude (R)-5 after 4 d
2. customThe product was purified by column chromatography (SiO2; 1/9 MeOH/CHCl3)