Regioselective enzymatic acylation of pharmacologically interesting nucleosides in 2-methyltetrahydrofuran, a greener substitute for THF

Abstract

1-β-Arabinofuranosyl uracil, 9-β-arabinofuranosyl adenosine, 2′-O-(2-methoxyethyl)-5-methyl uridine, adenosine and uridine were enzymatically acylated with hexanoic anhydride and vinyl esters by CALB lipase (lipase B from Candida antarctica) with excellent regioselectivity in many cases and analytical reaction yields above 90%. The influence of the stereochemistry of the hydroxyl group on C-2′ was studied. Some of these esterifications were carried out in 2-methyltetrahydrofuran (MeTHF), which is described as an excellent substitute for THF in biocatalysed processes in organic media. This application for this green solvent is a proof-of-concept opening the use of MeTHF in biotransformations.