ORGN 697 |
Highly regioselective acylation of 5-fluorouridine with vinyl benzoate catalyzed by lipozyme TL IM, an inexpensive lipase from Thermomyces lanuginose, for the preparation of 5′-O-benzoyl-5-fluorouridine has been successfully performed for the first time. The product was confirmed to be 5′-O-benzoyl-5-fluorouridine by 13C NMR. Compared with a single organic solvent, lipozyme TL IM displayed higher activity towards 5-fluorouridine in co-solvent mixtures. With the hexane-THF (50:50, v/v) co-solvent system, the reaction efficiency was substantially enhanced. Under the optimized conditions, with the initial water activity, the molar ratio of vinyl benzoate to 5-fluorouridine and the reaction temperature being 0.07, 20:1 and 60 °C, respectively, the initial reaction rate, substrate conversion and regioselectivity were 8.4 mM/h, 98.8% and >99%, respectively. |
Heterocycles and Aromatics, Asymmetric Reactions and Syntheses and Total Synthesis of Complex Molecules
7:00 PM-9:00 PM, Wednesday, August 19, 2009 Walter E. Washington Convention Center -- Ballroom C, Poster
Division of Organic Chemistry |