반응 #430489

반응 방정식

magnesium

HCl

bromoethane

17-Methyleneestra-1,3,5(10)-trien-3-ol

17-methyleneestra-1,3,5(10)-trien-3-ol

hexamethylphosphoric triamide

paraformaldehyde

→

23

수율 78.2%

3-hydroxy-17-methyleneestra-1,3,5(10)-triene-2-carboxaldehyde

수율 78.2%

용매

THF

THF

THF

benzene

반응 조건

후처리

1. 1
   workup.ADDITIONwas added to the reaction mixture
2. 2
   기타The solvent was removed at reduced pressure
3. 3
   workup.STIRRINGStirring
4. 4
   workup.WAITwas continued for 6 h at 80° C
5. 5
   추출the mixture extracted with EtOAc
6. 6
   세척The combined organic layers were washed with H2O
7. 7
   건조with saturated aqueous NaCl, and dried (Na2SO4)
8. 8
   여과The desiccant was filtered
9. 9
   기타the solvent was evaporated at reduced pressure
10. 10
    기타The residue was purified by column chromatography (silica gel)

실험 절차

To a suspension of magnesium (0.365 g, 15 mmol) in THF (3.0 mL) was added bromoethane (1.5 mL, 20 mmol) dissolved in THF (3.0 mL) at room temperature. 17-Methyleneestra-1,3,5(10)-trien-3-ol (19, 0.805 g, 3.0 mmol) dissolved in THF (7.5 mL) was added to the reaction mixture, and stirring continued for 30 min. The solvent was removed at reduced pressure, and to the residue were added benzene (35 mL), hexamethylphosphoric triamide (1.4 mL, 7.5 mmol) and paraformaldehyde (0.630 g). Stirring was continued for 6 h at 80° C. After the reaction mixture was cooled to room temperature, 5N HCl (15 mL) was added and the mixture extracted with EtOAc. The combined organic layers were washed with H2O, then with saturated aqueous NaCl, and dried (Na2SO4). The desiccant was filtered and the solvent was evaporated at reduced pressure. The residue was purified by column chromatography (silica gel) using n-hexane:AcOEt (10:1→3:1, v/v) to afford 0.695 g of 23 (78% yield), m.p. 128°-130° C.

출처