反应详情

12.5 mL of Jones reagent (33.3 mmol Cr(VI)) are dropped into a solution of 17.8 g of (3β,5β,12α)-3-azido-12-hydroxycholan-24-oic acid methyl ester (41.1 mmol) (prepared analogously to the method described for (3β,5β,7α,12α)-3-azido-7,12-dihydroxycholan-24-oic acid methyl ester in WO-A-95/32741: example 5) in acetone (600 mL) in 90 min at room temperature. After 20 h the mixture is filtered and the solution is evaporated. The residue is dissolved in CHCl3 (400 mL) and the solution is washed with a NaHCO3 saturated aqueous solution then with H2O. The solution is dried and evaporated to give a crude which is crystallized from 96% EtOH to obtain 14.1 g of the desired product (32.9 mmol).

1. customprepared analogously to the method
2. customin 90 min
3. customat room temperature
4. filtrationAfter 20 h the mixture is filtered
5. customthe solution is evaporated
6. dissolutionThe residue is dissolved in CHCl3 (400 mL)
7. washthe solution is washed with a NaHCO3 saturated aqueous solution
8. customThe solution is dried
9. customevaporated
10. customto give a crude which
11. customis crystallized from 96% EtOH