反应详情

3-Oxo-5β-cholan-24-oic acid (3.0 g) was dissolved in dry tetrahydrofuran (40 ml), cooled on an ice-bath, and over 15 min. 17.5 ml of 1.1 M solution of Lithium tri-tert-butoxyaluminohydride was added with stirring. Further 10 ml of tetrahydrofuran was added and stirring was continued for 15 min on an ice-bath and 1.5 hours at room temperature. After cooling the mixture on an ice-bath, the reaction was quenched by addition of 16 ml of water, followed by 20 ml of 6M HCl. The mixture was extracted with dichloromethane and the combined organic phases were washed with 1 M HCl and water and dried (Na2SO4). Removal of the solvent under reduced pressure gave 3.0 g of crude lithocholic acid. NMR analysis (CDCl3, 300 MHz) of the product showed characteristic signal at 0.66 (3H,s); 0.93 (6H, s and d); 2.15-2.49 (2H, m); 3.63 (1H, m), in accordance with the 1H-NMR spectrum of reference lithocholic acid.

1. temperaturecooled on an ice-bath
2. stirringstirring
3. waitwas continued for 15 min on an ice-bath and 1.5 hours at room temperature
4. temperatureAfter cooling the mixture on an ice-bath
5. customthe reaction was quenched by addition of 16 ml of water
6. extractionThe mixture was extracted with dichloromethane
7. washthe combined organic phases were washed with 1 M HCl and water
8. dry with materialdried (Na2SO4)
9. customRemoval of the solvent under reduced pressure