反应详情

Potassium tert-butoxide (220 mg, 1.96 mmol) was added to dry THF (5 ml) and stirred for 10 minutes to complete dissolution of the salt. Methyl triphenylphosphonium bromide (700 mg, 1.96 mmol) was added portionwise to the salt solution. Estrone (500 mg, 1.85 mmol) was dissolved in THF (5 ml) and added dropwise via a syringe to the bright yellow solution. After stirring at room temperature for 2 h, the reaction was heated at reflux overnight. The reaction was cooled, water added (10 ml) and the mixture extracted using ethyl acetate (3×10 ml). The combined organic fractions were combined, washed with water (2×10 ml) and brine (10 ml), dried (Na2SO4) and concentrated in vacuo. Flash column chromatography (SiO2 hexane:ethyl acetate 9:1) and recrystallisation from toluene/hexane afforded alkene 11 as a white crystalline solid (53 mg, 0.198 mmol, 11%). m.p. 130-132° C. (lit. m.p. 134-137° C.). δH (CDCl3) 0.82 (3H, s CH3), 1.20-1.62 (6H, m, alkyl H), 1.78-1.85 (1H, m, alkyl H), 1.90-1.99 (2H, m, alkyl H), 2.16-2.38 (3H, m, alkyl H), 2.50-2.59 (1H, m, alkyl H), 2.78-2.92 (2H, m, alkyl H), 4.50 (1H, s, OH), 4.67 (2H, t, J=2.0, olefinic H), 6.57 (1H, d, J=2.7, ArH-4), 6.63 (1H, dd, J=8.6, 2.7, ArH-2), 7.17 (1H, d, J=8.6, ArH-1).

1. dissolutiondissolution of the salt
2. additionadded dropwise via a syringe to the bright yellow solution
3. stirringAfter stirring at room temperature for 2 h
4. temperaturethe reaction was heated
5. temperatureat reflux overnight
6. temperatureThe reaction was cooled
7. extractionthe mixture extracted
8. washwashed with water (2×10 ml) and brine (10 ml)
9. dry with materialdried (Na2SO4)
10. concentrationconcentrated in vacuo
11. customFlash column chromatography (SiO2 hexane:ethyl acetate 9:1) and recrystallisation from toluene/hexane