Abstract: A 4-desoxy-4-epipodophyllotoxin derivative of the following formula ##STR1## wherein R and R.sub.1 are as defined in the specification or a pharmaceutically acceptable salt thereof as well as an antitumor composition comprising such derivative or salt as an active ingredient.

Abstract: A 4-desoxy-4-epipodophyllotoxin derivative of the following formula ##STR1## wherein R and R.sub.1 are as defined in the specification or a pharmaceutically acceptable salt thereof as well as an antitumor composition comprising such derivative or salt as an active ingredient.

Abstract: A 4-desoxy-4-epipodophyllotoxin derivative of the following formula ##STR1## wherein R and R.sub.1 are as defined in the specification or a pharmaceutically acceptable salt thereof as well as an antitumor composition comprising such derivative or salt as an active ingredient.

Abstract: This invention provides a 5-substituted uridine derivative of the formula ##STR1## wherein X is F or CF.sub.3, R.sub.1 and R.sub.2 each represent a group --OSi--(R.sub.4)(R.sub.5)(R.sub.6) (wherein R.sub.4, R.sub.5 and R.sub.6 represent C.sub.1 -C.sub.10 alkyl or the like), OH, aminoacyloxy group wherein the amino group may be substituted with lower alkyl group or carboxylalkylcarbonyloxy group, R.sub.3 is a group --OSi(R.sub.4)(R.sub.5)(R.sub.6), H, OH, aminoacyloxy group wherein the amino group may be substituted with lower alkyl group, or carboxylalkylcarbonyloxy group, and at least one of R.sub.1, R.sub.2 and R.sub.3 is a group --OSi--(R.sub.4)(R.sub.5)(R.sub.6), with the proviso that when X is fluorine atom, R.sub.3 is not hydrogen, and an intermediate for the preparation thereof, preparation processes of the derivative and anti-tumor agent containing the derivative as an active ingredient.

Abstract: Novel 2'-deoxy-5-substituted uridine derivative represented by the general formula, ##STR1## wherein R.sub.1 is a hydrogen atom, a benzoyl group or a tetrahydrofuranyl group; R.sub.2 is a fluorine atom or a trifluoromethyl group; and any one of R.sub.3 and R.sub.4 is a hydrogen atom and the other one is an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a benzyl group having as the substituents selected from the group consisting of a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms and a nitro group, or an alkyl group having 1 to 3 carbon atoms having one or two phenyl groups as the substituents.The novel 2'-deoxy-5-substituteduridine derivative possesses excellent antitumor activity with less toxicity, thus it is useful as antitumor agent.

Abstract: Novel 2'-deoxy-5-substituted uridine derivative represented by the general formula, ##STR1## wherein R.sub.1 is a hydrogen atom, a benzoyl group or a tetrahydrofuranyl group; R.sub.2 is a fluorine atom or a trifluoromethyl group; and any one of R.sub.3 and R.sub.4 is a hydrogen atom and the other one is an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a benzyl group having as the substituents selected from the group consisting of a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms and a nitro group, or an alkyl group having 1 to 3 carbon atoms having one or two phenyl groups as the substituents.The novel 2'-deoxy-5-substituteduridine derivative possesses excellent antitumor activity with less toxicity, thus it is useful as antitumor agent.