反应详情

Under a nitrogen atmosphere, (1S)-camphanic acid chloride (3.37 g, 15.6 mmol) was added to a solution of (RS)-1-(2-nitrophenyl)-2,2-dimethyl-1-propanol (2.71 g, 13 mmol) and DMAP (80 mg, 0.65 mmol) in anhydrous pyridine (50 mL). The mixture was stirred for 24 hours at room temperature. Solvent was removed in vacuo, and the residue was dissolved in ethyl acetate (50 mL), washed with 0.5 M HCl (20 mL) twice followed with saturated NaHCO3 solution (20 mL). The organic phase was dried over Na2SO4, concentrated in vacuo and purified by silica gel column chromatography to yield (RS)-1-(2-nitrophenyl)-2,2-dimethyl-1-propyl (1S)-camphanate (4.11 g, 81%, 1:1 mixture of diastereomers) as a yellow solid. 1H NMR (400 MHz, CDCl3) for diastereomers: δ 7.91 (m, 1H, Ph-H), 7.62 (m, 2H, Ph-H), 7.46 (m, 1H, Ph-H), 6.66 and 6.62 (2 s, 1H, Ph-CH), 2.38 (m, 1H), 2.10-1.9 (m, 2H), 1.71 (m, 1H), 1.13, 1.11, 1.08, 1.04, 1.03, 0.87 (6 s, 9H, CH3×3), 0.97 (s, 9H, (CH3)3C).

1. customSolvent was removed in vacuo
2. dissolutionthe residue was dissolved in ethyl acetate (50 mL)
3. washwashed with 0.5 M HCl (20 mL)
4. dry with materialThe organic phase was dried over Na2SO4
5. concentrationconcentrated in vacuo
6. custompurified by silica gel column chromatography