反应详情

4-Cholesten-3,6-dione was prepared using 4-cholesten-3-one (Aldrich Co.) as a starting material by reference to the method of Hevl and Herr (F. W. Hevl and M. E. Herr, J. Am. Chem. Soc., 75: 1918, 1953) and that of Malhotra et al. (S. K. Malhotra, J. J. Hostynek and A. F. Lundin, J. Am. Chem. Soc., 90: 6565, 1968). Stated specifically, pyrrolidine (2.85 g) was added to a benzene solution (50 ml) of 4-cholesten-3-one (3.84 g) and the mixture was refluxed under heating for 24 hours. After cooling, the solvent and the excess pyrrolidine were distilled off under vacuum. Upon recrystallization from methanol, a colorless crystal of dienamine (4.16 g) was obtained. Cupric acetate (100 mg) was added to a benzene-methanol (500:10) solution of the dienamine (4.16 g) and air was introduced into the mixture for 24 hours. Then, a 2% aqueous solution (20 ml) of acetic acid was added and the mixture was stirred for 30 minutes and washed successively with water, a 1% sodium carbonate solution and a saturated saline solution. The resulting residue was dried, filtered and subjected to silica gel column chromatography (hexane:ethyl acetate=10:1) to yield a colorless crystal of 4-cholestene-3,6-dione (3.23 g).

1. custom4-Cholesten-3,6-dione was prepared
2. temperaturethe mixture was refluxed
3. temperatureunder heating for 24 hours
4. temperatureAfter cooling
5. distillationthe solvent and the excess pyrrolidine were distilled off under vacuum
6. customUpon recrystallization from methanol
7. customa colorless crystal of dienamine (4.16 g) was obtained
8. additionwas introduced into the mixture for 24 hours
9. washwashed successively with water
10. customThe resulting residue was dried
11. filtrationfiltered