Water → 7-O-(Triethylsilyl)-10-deacetyl Baccatin III

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

544 mg (1 mmol) of 10-deacetylbaccatine III, dissolved in 50 cm3 of anhydrous pyridine, are introduced under an argon atmosphere into a 100-cm3 round-bottomed flask equipped with a magnetic stirrer. 3.36 cm3 (3.014 g; 20 mmol) of triethylsilyl chloride are then added. The homogeneous, yellow reaction mixture is then stirred for 24 hours at 0° C. Ethyl acetate and water are then added. After settling has taken place, the separated aqueous phase is extracted with ethyl acetate. The combined organic phases are treated with saturated aqueous copper sulphate solution until the pyridine has been completely removed. The organic phases are washed with water and then with saturated sodium chloride solution, and then dried over anhydrous sodium sulphate. After filtration and evaporation of the solvents under reduced pressure, 2.73 g of a product are obtained, and this is purified on a silica column, eluting with a dichloromethane/methanol (99:1 by volume) mixture. 512 mg (0.778 mmol) of 10-deacetyl-7-triethylsilylbaccatine III are thereby obtained, in a 78% yield, in the form of a white solid, the characteristics of which are as follows:

Herkunft & Nachweise