反应详情

To a solution of tert-butyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-formyl-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl)benzoate (0.1 g, 0.167 mmol) in DCE (2 ml) was added acetic acid (0.019 ml, 0.334 mmol) and N-acetylethylenediamine (0.048 ml, 0.501 mmol). The mixture was stirred for 2 h at rt then to the mixture was added sodium triacetoxyborohydride (0.177 g, 0.835 mmol). The mixture was stirred at rt for 3 days then was diluted with 7 ml of sat. NaHCO3 and was extracted with dichloromethane (3×7 ml). The combined organic layers were dried with Na2SO4, the drying agent was removed by filtration, and the filtrate was concentrated under reduced pressure. The crude material was used in the next step with no additional purification. LCMS: m/e 685.4 (M+H)+, 3.86 min (method 6).

1. stirringThe mixture was stirred at rt for 3 days
2. extractionwas extracted with dichloromethane (3×7 ml)
3. dry with materialThe combined organic layers were dried with Na2SO4
4. customthe drying agent was removed by filtration
5. concentrationthe filtrate was concentrated under reduced pressure
6. customThe crude material was used in the next step with no additional purification
7. customm/e 685.4 (M+H)+, 3.86 min (method 6)