반응 #172823

반응 방정식

methyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-amino-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

3-formyl-piperidine-1-carboxylic acid tert-butyl ester

sodium triacetoxyborohydride

→

title compound

수율 70.9%

tert-butyl 3-(((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-9-(4-(methoxycarbonyl)phenyl)-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-3a-ylamino)methyl)piperidine-1-carboxylate

수율 70.9%

용매

DCE

NaHCO3

반응 조건

후처리

1. 1
   workup.STIRRINGAfter stirring the mixture for 16.5 h
2. 2
   추출was extracted with dichloromethane (3×5 mL)
3. 3
   건조The combined organic layers were dried with Na2SO4
4. 4
   기타The drying agent was removed by filtration
5. 5
   농축the filtrate was concentrated under reduced pressure
6. 6
   기타was purified by silica gel flash chromatography
7. 7
   workup.ADDITIONThe fractions containing the expected product
8. 8
   농축concentrated under reduced pressure

실험 절차

To a solution of methyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-amino-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 (30 mg, 0.055 mmol) in DCE (0.5 mL) was added 3-formyl-piperidine-1-carboxylic acid tert-butyl ester (14.71 mg, 0.069 mmol) and titanium(IV) isopropoxide (0.020 mL, 0.069 mmol). The mixture was stirred at rt for 1 h and sodium triacetoxyborohydride (23.38 mg, 0.110 mmol) was added. After stirring the mixture for 16.5 h, the mixture was diluted with 3 mL of sat. NaHCO3 and was extracted with dichloromethane (3×5 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 residue was adsorbed to silica gel and was purified by silica gel flash chromatography using a 0-10% EtOAc in hexanes gradient and a Thomson 12 g silica gel column. The fractions containing the expected product were combined and concentrated under reduced pressure to afford the title compound (29 mg, 0.039 mmol, 70.9% yield) as an off-white film. The product was used in the next step with no additional purification. LCMS: m/e 741.7 (M+H)+, 3.76 min (method 2).

출처