Reaktion #51639

Reaktionsgleichung

acetic acid

diacetate

2-Methoxy-3,17-diacetoxyestra-1,3,5(10),14,16-pentaene

sodium borohydride

→

product ( 18 )

2-Methoxyestra-1,3,5(10),14-tetraen-3,17β-diol

Lösungsmittel

water

ethanol

THF

ethanol water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto warm to room temperature
2. 2
   workup.STIRRINGstirred overnight
3. 3
   SonstigeThe organic solvents were removed in vacuo under a stream of nitrogen
4. 4
   workup.ADDITIONthe residue was diluted with water (50 mL)
5. 5
   Extraktionextracted with methylene chloride (3×)
6. 6
   WaschenThe organic fractions were washed with water (2×), brine (1×)
7. 7
   Filtrationfiltered through sodium sulfate
8. 8
   Einengenconcentrated in vacuo
9. 9
   SonstigeThe residue was triturated with ether

Vorschrift

A solution of the diacetate (17) (0.08 g, 0.21 mmol) in ethanol (5 mL) and THF (3 mL) was cooled to 0° C. in an ice bath. A solution of sodium borohydride (0.05 g, 1.32 mmol) in ethanol/water (10:3, 5 mL) was cooled to 0° C. in an ice bath and added to the steroid solution. The reaction mixture was stirred at 0° C. for 1 h., then allowed to warm to room temperature and stirred overnight. After that time, the reaction was diluted with water (20 mL) and neutralized with glacial acetic acid. The organic solvents were removed in vacuo under a stream of nitrogen, the residue was diluted with water (50 mL) and extracted with methylene chloride (3×). The organic fractions were washed with water (2×), brine (1×), filtered through sodium sulfate, combined and concentrated in vacuo. The residue was triturated with ether to give the pure product (18) (0.035 g, 55.7%.

Quelle