A lipase from Pseudomonas sp. (Amano PS) catalyzes regioselective acylation of the 3'-hydroxyl groups of FUclR and CF3UdR.
FUdR and CF3UdR are highly attractive compounds as anti-cancer and anti-viral drugs. 1 v2 In order to synthesize these compounds, regioselective protection of the functional groups in these nucleosides is quite important. There is no report on direct regioselective acylation of a hydroxyl group of the nucleosides, both chemically and enzymatic method.
Lipase-catalyzed regioselective acylation of hydroxyl groups in the sugar moieties of pyrimidinenucleosides in aprotic polar solvents such as DMF, DMA, and DMSO has been reported previously.3 However, the selective acylation between 3'-and S-hydmxyl groups was not satisfactory&creasing polarity of the solvent tends to increase the regioselectivity. FUdR and CF3UdR are found to be soluble in dioxane.
In this paper, we wish to report an enzymatic mono-acylation of these nucleosides in dioxane. The reaction of the above nucleosides with acetic anhytide.,vinyl acetate or hexanoic anhydride in the presence of Amano PS ( a lipase from Pseudomonas sp.) afforded preferentially the 3'-acyl derivatives as shown in Table