反应详情

To a solution of benzyl 2,5-dioxocyclopentanecarboxylate (2.58 g, 10.35 mmol) in MeOH (20 mL) at 0° C. was added 2-aminocyclohexanol (1.25 g, 10.87 mmol). The reaction mixture was stirred at room temperature for 18 hr and quenched by addition of 0.25 N HCl (8 mL). MeOH was removed in vacuo and the aqueous layer was extracted with CH2Cl2 (4×10 mL). The combined organic portions were washed with saturated NaCl (20 mL), dried over Na2SO4, filtered and concentrated under reduced pressure. The resulted brown oil was purified by ISCO chromatography (40 g column) using hexanes/EtOAc (0-5% over 15 min, 5-10% over 7 min) to give benzyl 2-hydroxycyclohexylcarbamate as a light yellow solid at a retention time of 11-13 min (2.15 g, 83% yield) HPLC: RT=2.83 min, Purity 95% (HPLC Method 1) NMR: 400 MHz 1H (CDCl3) 7.33 ppm, 5 H, m; 5.16 ppm, 1 H, m; 5.09 ppm, 2 H, s; 3.95 ppm, 1 H s; 3.68 ppm, 1 H m; 1.54 ppm, 8 H, m.

1. customquenched by addition of 0.25 N HCl (8 mL)
2. customMeOH was removed in vacuo
3. extractionthe aqueous layer was extracted with CH2Cl2 (4×10 mL)
4. washThe combined organic portions were washed with saturated NaCl (20 mL)
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customThe resulted brown oil was purified by ISCO chromatography (40 g column)
9. customhexanes/EtOAc (0-5% over 15 min, 5-10% over 7 min)