SYNTHESIS AND ANTIVIRAL ACTIVITY OF 7-O-(OMEGA-SUBSTITUTED)-ALKYL-3-O-METHYL-QUERCETIN DERIVATIVES

3',4'-Di-O-benzyl-3-O-methylquercetin (2), the precursor in the synthe sis of an important antivirally active flavone 3-O-methylquercetin (1) , was regioselectively alkylated at the 7-OH position by a series of 1 ,omega-dihaloalkanes and omega-bromoalkanols. Dimerization of the flav one had to be avoided by applying strict reaction conditions. Subseque nt debenzylation was carried out by catalytic transfer hydrogenolysis, affording quantitatively the 7-O-(omega-haloalkyl)-3-O-methylquerceti n (11-14) and 7-O-(omega-hydroxyalkyl)-3-O-methylquercetin derivatives (15, 16). All compounds were tested for their antiviral activity agai nst poliomyelitis- and HIV-viruses.