Reaktion #430484

Reaktionsgleichung

trifluoroacetic acid

HCl

estradiol

hexamethylenetetramine

potassium carbonate

→

2a

Ausbeute 13.0%

3,17β-dihydroxyestra-1,3,5(10)-triene-2-carboxaldehyde

Ausbeute 13.0%

2b

Ausbeute 4.0%

3,17β-dihydroxyestra-1,3,5(10)-triene-4-carboxaldehyde

Ausbeute 4.0%

Lösungsmittel

EtOAc

MeOH

H2O

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted with Et2O
2. 2
   WaschenThe combined organic layers were washed with H2O
3. 3
   Trocknenwith saturated aqueous NaCl, and dried (MgSO4)
4. 4
   FiltrationThe desiccant was filtered
5. 5
   Sonstigethe solvent was evaporated at reduced pressure
6. 6
   workup.DISSOLUTIONThe residue was dissolved in THF (50 mL)
7. 7
   workup.STIRRINGthe mixture stirred for 1 h at room temperature
8. 8
   Extraktionextracted with EtOAc
9. 9
   WaschenThe combined organic layers were washed with H2O
10. 10
    Trocknenwith saturated aqueous NaCl, and dried (MgSO4)
11. 11
    FiltrationThe desiccant was filtered
12. 12
    Sonstigethe solvent was evaporated at reduced pressure
13. 13
    SonstigeThe residue was purified by column chromatography (silica gel)

Vorschrift

To a mixture of estradiol (1, 13.6 g, 50 mmol) and hexamethylenetetramine (21.0 g, 150 mmol) was added trifluoroacetic acid (100 mL) at room temperature. The reaction mixture was stirred for 6 h at 100° C., poured into H2O (300 mL), and extracted with Et2O. The combined organic layers were washed with H2O, then with saturated aqueous NaCl, and dried (MgSO4). The desiccant was filtered and the solvent was evaporated at reduced pressure. The residue was dissolved in THF (50 mL) and MeOH (50 mL), potassium carbonate (6.9 g, 50 mmol) was added, and the mixture stirred for 1 h at room temperature. The reaction mixture was then diluted with EtOAc, acidified with 1N HCl, and extracted with EtOAc. The combined organic layers were washed with H2O, then with saturated aqueous NaCl, and dried (MgSO4). The desiccant was filtered and the solvent was evaporated at reduced pressure. The residue was purified by column chromatography (silica gel) using n-hexane:THF (5:1→3:1, v/v) to afford 1.91 g of 2a (13% yield), m.p. 219°-221° C., and 0.552 g of 2b (4% yield), m.p. 146°-147° C.

Quelle