反应详情

To a mixture of methyl 2-oxo-3-(3-phenylpropyl-1-yl)cyclopentanecarboxylate (1 g, 3.8 mmol) in hexane (40 mL) is added phosphorus pentachloride (1.5 g, 7.6 mmol). The mixture is heated under reflux for 2.5 hours. The solution is cooled in ice and methanol (few mL) is added. The mixture is stirred at room temperature for 15 minutes. The mixture is poured into water and is extracted with hexane. The organic layer is washed with water and is dried over MgSO4. The organic layer is removed in vacuo and the residue is dissolved in dichloromethane. To this solution is added 2 M oxalyl chloride (few mL). The mixture is stirred at room temperature for 2 hours. The solvent is removed in vacuo and the residue is dissolved in dichloromethane and methanol (few mL) is added. The solution is stirred at room temperature for 15 minutes. The solvent is removed in vacuo and the residue is chromatographed on silica gel (20:1 hexane:ethyl acetate) to give methyl 2-chloro-3-(3-phenylpropyl-1-yl)-1-cyclopentenecarboxylate (0.2 g, 20%): 1H-NMR (300 MHz, CDCl3) δ (TMS) 1.50-1.70 (m, 4H), 1.78-1.92 (m, 1H), 2.07-2.19 (m, 1H), 2.53-2.71 (m, 4H), 2.78-2.92 (m, 1H), 3.78 (s, 3H), 7.17-7.32 (m, 5H); MS (EI) m/e 278 (M+).

1. temperatureThe mixture is heated
2. temperatureunder reflux for 2.5 hours
3. temperatureThe solution is cooled in ice
4. extractionis extracted with hexane
5. washThe organic layer is washed with water
6. dry with materialis dried over MgSO4
7. customThe organic layer is removed in vacuo
8. dissolutionthe residue is dissolved in dichloromethane
9. additionTo this solution is added 2 M oxalyl chloride (few mL)
10. stirringThe mixture is stirred at room temperature for 2 hours
11. customThe solvent is removed in vacuo
12. dissolutionthe residue is dissolved in dichloromethane
13. additionmethanol (few mL) is added
14. stirringThe solution is stirred at room temperature for 15 minutes
15. customThe solvent is removed in vacuo
16. customthe residue is chromatographed on silica gel (20:1 hexane:ethyl acetate)