Reaktion #472350

Reaktionsgleichung

water

Ethyl aluminum dichloride

methyl acrylate

compound 1.6a

(Z)-3α-Acetoxy-5β-pregna-9(11), 17(20)-diene

→

compound 1.7b

Ausbeute 70.0%

Methyl 3α-acetoxy-5β-chol-9(11), 16-dien-24-oate

Ausbeute 70.0%

Lösungsmittel

DCM

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGAfter stirring for an additional 20 min at 0° C.
2. 2
   workup.WAITheld there for a further 18 h
3. 3
   SonstigeThe phases were separated
4. 4
   Extraktionthe aqueous layer was extracted with DCM (60 mL)
5. 5
   Waschenwashed sequentially with water (50 mL) and saturated brine solution (100 mL)
6. 6
   TrocknenIt was then dried over anhydrous Na2SO4 (5 g)
7. 7
   Filtrationfiltered
8. 8
   EinengenThe filtrate was concentrated under vacuum

Vorschrift

Ethyl aluminum dichloride (14.2 mL, 25 mmol, 1.8M in toluene) was added to a solution of methyl acrylate (1.89 mL, 20 mmol) in DCM (60 mL) at 0° C. under inert atmosphere. The resulting solution was stirred for 15 min and then compound 1.6a (3 g, 8.7 mmol) was added. After stirring for an additional 20 min at 0° C., the temperature was raised to 25° C. and held there for a further 18 h. At this point the reaction was determined to be complete by TLC, then the mixture was poured into cold (0° C.) water (60 mL). The phases were separated and the aqueous layer was extracted with DCM (60 mL). The organic layers were combined and washed sequentially with water (50 mL) and saturated brine solution (100 mL). It was then dried over anhydrous Na2SO4 (5 g) and filtered. The filtrate was concentrated under vacuum, providing compound 1.7b (2.6 g, 70%).

Quelle