Abstract: A process for producing a 3-alkoxy-2-amino-6-fluoro bicyclo[3.1.0]hexane-2,6-dicarboxylic acid derivative represented by the formula (I) or a salt thereof, which includes converting a compound represented by the formula (VI) or a salt thereof to the compound represented by the formula (I) or a salt thereof.

Abstract: A process for producing a 3-alkoxy-2-amino-6-fluoro bicyclo[3.1.0]hexane-2,6-dicarboxylic acid derivative represented by the formula (I) or a salt thereof, which includes converting a compound represented by the formula (VI) or a salt thereof to the compound represented by the formula (I) or a salt thereof.

Abstract: A process for producing a 3-alkoxy-2-amino-6-fluoro bicyclo[3.1.0]hexane-2,6-dicarboxylic acid derivative represented by the formula (I) or a salt thereof, which includes converting a compound represented by the formula (VI) or a salt thereof to the compound represented by the formula (I) or a salt thereof.

Abstract: Aminobenzoic acid derivatives represented by Formula (1) as follows: (wherein, R1 represents a hydrogen atom, a C1-6alkyl group, or the like; R2 represents a hydrogen atom, a C1-6alkyl group, or the like; R3 represents a C8-25alkyl group, or the like; R4 represents a hydrogen atom or a group represented by OR9 or CO2R10 (wherein R9 and R10 represent a hydrogen atom or a C1-6 alkyl group); A represents a group represented by S(O)qR15 (wherein q is 0, 1, or 2, R15 represents a C1-6alkyl group, a phenyl C1-3alkyl group, or a group represented by (CH2)mOR16 (wherein m is 2 or 3, and R16 represents a hydrogen atom or a methoxymethyl group), or the like; X represents O, a single bond, CH═CH, or a group represented by NR27 (wherein R27 represents a hydrogen atom or a t-butoxycarbonyl group); Y represents O, CONH, NHCO, or a group represented by NR28 (wherein R28 represents a hydrogen atom or a t-butoxycarbonyl group); and n is an integer of 0 to 15) or pharmaceutically acceptable salts of the

Abstract: To provide novel steroid derivatives having an antitumor action which can be synthesized efficiently and stereoselectively by means of synthetic organic chemistry. A steroid derivative represented by the formula: ##STR1## wherein R is an alkyl group having 1 to 13 carbon atoms, A is a hydroxyl group or a group easily hydrolyzable to a hydroxyl group, X and Y together form an oxo group or an alkylenedioxy group having 2 or 3 carbon atoms, X is a hydroxyl group, an alkoxy group having 1 to 5 carbon atoms or a group easily hydrolyzable to a hydroxyl group, Y is a hydrogen atom or an alkoxy group having 1 to 5 carbon atoms, with the proviso that when X is a hydroxyl group or a group easily hydrolyzable to a hydroxyl group, Y is a hydrogen atom, and when X is an alkoxy group having 1 to 5 carbon atoms, Y is an alkoxy group having 1 to 5 carbon atoms, or a salt thereof.

Abstract: Indolo[2,3-b]quinoxaline derivatives represented by the following formula: ##STR1## wherein one of R.sup.1 and R.sup.2 is a hydrogen atom and the other is a group of the formula:--CH.sub.2 NHCCH.sub.3 (CH.sub.2 OH).sub.2,etc, and R.sup.3 is a hydrogen atom, a methyl group, etc.; and pharmaceutically acceptable salts thereof have an antitumor activity and are useful as medicines.