反应详情

The mixture of pentafluorophenyl ester of Cholest-5-en-3β-yloxyacetic acid (175 mg, 0.29 mmol) and 15-amino-4,7,10,13-tetraoxapentadecanoic acid (160 mg, 0.60 mmol) was dried in an apparatus equipped with septum for 4 h at room temperature and 0.1 Pa. The apparatus was flushed with argon (2×) and then dry N,N-dimethylformamide (6 ml) and N-ethyldiisopropylamine (2 ml) were added through the septum and the mixture was stirred at room temperature for 16 h. Flash chromatography of the crude reaction mixture on silica gel column (200 ml) in toluene-ethyl acetate (gradient: 0-80% ethyl acetate, 10 ml/min, 160 min) gave (cholest-5-en-3β-yloxy)acetyl-15-amino-4,7,10,13-tetraoxapentadecanol acid (general formula X, where n3=1 and n4=3; 167 mg, 84%). For C40H69NO8Na HR-MS, calculated: m/z: 714.4915. found: m/z: 714.4916; 1H NMR (400 MHz, CDCl3) δ ppm: 5.34-5.38 m, 1H (CH2-5′); 4.00 s, 2H (CH2COO); 3.78 t, J=6.06 Hz, 2H (CH2-3); 3.59-3.68 m, 14H (7×CH2O); 3.52 q, J=5.47 Hz, 2H (CH2-14); 3.23 tt, J=11.24, 4.36 Hz, 1H (CH-3′); 2.61 t, J=6.00 Hz, 2H (CH2-2); 2.36 ddd, J=13.20, 4.70 (CH-4′a); 2.19-2.29 m, 1H (CH-4′b); 1.77-2.06 m, 5H (cholesteryl); 1.00 s, 3H (CH3-19′); 1.29 d, J=3.66 Hz, 24H (cholesteryl); 0.92 d, J=6.57 Hz, 3H (CH3-21′); 0.88 d, J=1.89 Hz, 3H (CH3-26′); 0.86 d, J=1.77 Hz, 3H (CH3-27′); 0.68 s, 3H (CH3-18′).

1. customwas dried in an apparatus
2. customequipped with septum for 4 h at room temperature
3. customThe apparatus was flushed with argon (2×)
4. additiondry N,N-dimethylformamide (6 ml) and N-ethyldiisopropylamine (2 ml) were added through the septum
5. customFlash chromatography of the crude reaction mixture on silica gel column (200 ml) in toluene-ethyl acetate (gradient: 0-80% ethyl acetate, 10 ml/min, 160 min)