Reaktion #50340

Reaktionsgleichung

9α-Bromo-11β-hydroxyandrost-4-ene-3,17-dione

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title compound

11β-Hydroxyandrost-4-ene-3,17-dione

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigedegassed
2. 2
   workup.ADDITIONThis solution is added dropwise over 20 min to a freshly degassed slurry of chromic chloride hexahydrate (81 mg), thiovanic acid (0.70 ml) and zinc dust (555 mg) in DMF (4 ml) at 0° THF (about 8 ml)
3. 3
   Waschenfor rinse purposes
4. 4
   Temperaturis slowly heated to 50°
5. 5
   SonstigeThe THF is removed by vacuum distillation
6. 6
   workup.ADDITIONthe remaining slurry is diluted with ethyl acetate (25 ml) and water (25 ml)
7. 7
   SonstigeThe unreacted zinc is removed by filtration
8. 8
   Waschenis washed with aqueous ethyl acetate
9. 9
   WaschenThe combined filtrate and wash
10. 10
    Sonstigeto separate
11. 11
    WaschenThe organic layer is washed with water (3×25 ml)
12. 12
    Einengenfinally is concentrated under vacuum to a residue
13. 13
    SonstigeThe residue is recrystallized from 1 part toluene and 2 parts heptane

Vorschrift

9α-Bromo-11β-hydroxyandrost-4-ene-3,17-dione (I, PREPARATION 2, 2.134 g) is dissolved in THF (THF 20ml) and degassed as described in EXAMPLE 1. This solution is added dropwise over 20 min to a freshly degassed slurry of chromic chloride hexahydrate (81 mg), thiovanic acid (0.70 ml) and zinc dust (555 mg) in DMF (4 ml) at 0° THF (about 8 ml) is used for rinse purposes. The slurry is stirred at 0° to 2° for 2.2 hr and then is slowly heated to 50°. The THF is removed by vacuum distillation and the remaining slurry is diluted with ethyl acetate (25 ml) and water (25 ml). The unreacted zinc is removed by filtration and is washed with aqueous ethyl acetate. The combined filtrate and wash is allowed to separate. The organic layer is washed with water (3×25 ml) and finally is concentrated under vacuum to a residue. The residue is recrystallized from 1 part toluene and 2 parts heptane to give the title compound, TLC Rf =0.45 (methanol/methylene chloride, 5/95); HPLC 96.7% (II), 2.9% ∆9(11).

Quelle