Six novel 5-substituted-1-[2-(3-methoxy-2-hydroxyphenyl)-1-methoxyethyl]uracils 2a-f were prepared by condensation of 2,4-bis(trimethylsilyloxy)-5-substituted uracils with 2,7-dimethoxy-2,3-dihydrobenzofuran (9) in the presence of Lewis acid. The 2,3-dihydrobenzofuran derivative 9 was obtained by intramolecular acetalization of 2-acetoxy-3-methoxyphenyl acetaldehyde (8) which was synthesized by oxidative cleavage of 1-allyl-2-acetoxy-3-methoxybenzene (7) using osmium tetroxide followed by $NaIO_4$. Compounds 2a-f were evaluated for in vitro antiviral activity against HSV-1, HSV-2 and HRV. None of these compounds showed activity with $ID_{50}$ values up to $100;{mu}g/ml$ except for 5-chlorouracil derivative 2d which exhibited antiviral activity against HSV-1 with $ED_{50}$ $30;{mu}g/ml$. In the antitumor activity against L1210 and P388 leukemia cell lines, 2d showed activity with $ID_{50}$ values of $14;{mu}g/ml$ and $11.6;{mu}g/ml$, and 2c with $ID_{50}$ values of $22.9;{mu}g/ml$ and $8.8;{mu}g/ml$, respectively.