反应详情

A solution of 61 (407 mg, 1.57 mmol), DMAP (19 mg, 0.16 mmol) and Et3N (0.65 mL, 4.70 mmol) in THF (8 mL) was treated with Ac2O (0.22 mL, 2.35 mmol) and allowed to stir at room temperature for 16 h. The reaction mixture was diluted with Et2O, washed with H2O (2×10 mL), brine (1×10 mL), dried over Na2SO4, filtered, and all volatiles were removed in vacuo. The crude product was taken up in hexanes and filtered through a pad of silica gel, eluting with 60:40 hexane/EtOAc. Evaporation of the filtrate afforded acetate 62 (413 mg, 88%) as a dark orange oil: Rf=0.44 (silica, 50:50 hex/EtOAc); IR (KBr, neat) vmax 3095, 3014, 2947, 2848, 2783, 1736, 1486, 1454 cm−1; 1H NMR (300 MHz, CDCl3) δ 5.03 (AB q, 2H, J=12.0, 12.0 Hz), 4.16 (s, 5H), 4.10 (t, 1H, J=1.8 Hz), 4.02-3.93 (m, 2H), 2.61 (s, 6H), 2.03 (s, 1H), 13C NMR (75 MHz, CDCl3) δ 170.9, 114.4, 68.7, 67.7, 63.5, 61.9, 56.6, 45.2, 21.0; EIMS [m/z (%)] 301 (M+, 33), 121 (100); HRMS (EI) calcd for C15H19NO256Fe: 301.0765. Found 301.0766.

1. washwashed with H2O (2×10 mL), brine (1×10 mL)
2. dry with materialdried over Na2SO4
3. filtrationfiltered
4. customall volatiles were removed in vacuo
5. filtrationfiltered through a pad of silica gel
6. washeluting with 60:40 hexane/EtOAc
7. customEvaporation of the filtrate