反应详情

To a stirred solution of the above acid (37) (1.0 g) in dimethylformamide (20 mL) was added hydroxybenzotriazole (0.62 g), HCl.Val-Val-OMe (0.67 g), triethylamine (1.93 mL) followed by Bop reagent (1.93 g). After stirring at room temperature for 16 h the reaction was evaporated to dryness and flash chromatographed on silica gel eluted with 60% ethyl acetate in n-hexane to give the titled product (38) (0.95 g, 57%). TLC Rf 0.48, 0.41 (60% ethyl acetate, n-hexane) Rf 0.40, 0.37 (97:3 CHCl3 :MeOH); MS DCI/NH3 (M+H)+ =648.5; 1H NMR (CDCl3) δ0.8-1.0(12H, m) Val γ(CH3)2 's, 1.12(3H, d, J=7 Hz) Ala CH3, 3.7(3H, s) CO2CH3, 5.1(2H, s) Cbz CH2, 5.4(1H, d) vinyl CH, 7.22(5H, s) phenyl, 7.46(5H, s) Cbz phenyl.

1. customwas evaporated to dryness and flash
2. customchromatographed on silica gel
3. washeluted with 60% ethyl acetate in n-hexane