摘要:
A process for preparing allenyl-β-lactam compounds of general formula (II) or 3-halocephem compounds of general formula (III) from halogenated β-lactam compounds of general formula (I) under reaction conditions selected depending on the objective compound. In formula (I), R1 is hydrogen, amino or protected amino; R2 is optionally substituted aryl; n is 0 to 2; R3 is hydrogen or a carboxyl-protecting group; X is halogeno; and Y is halogeno or a leaving group. In formula (II), R1, R2, n and R3 are each as defined above. In formula (III), R1, R3 and X are each as defined above.
摘要:
A process for producing a halogenated β-lactam compound, comprising halogenating the allenyl group of an allenyl-β-lactam compound of general formula (1) with a cupric halide and a metal halide into a halogenated β-lactam compound of general formula (2). In formula (1), R1 is hydrogen, amino or protected amino; R2 is hydrogen, halogeno, lower alkoxy, lower acyl or lower alkyl substituted with hydroxyl or protected hydroxyl; R3 is hydrogen or a carboxyl-protecting group; and R4 is optionally substituted hydrocarbyl or -S-S(O)¿n?-Ar (n being 0 to 2 and Ar being optionally substituted aryl). In formula (2), R?1, R2, R3 and R4¿ are each as defined above; and X and Y are each halogeno.
摘要:
A β-lactam compound and a 2-(substituted methyl)-3-cephem compound, both being useful as an intermediate for the synthesis of cephem antibiotics and so forth. The lactam compound is represented by general formula (I), wherein R1 represents protected amino, etc.; R2 represents hydrogen, etc.; R3 represents hydrogen or a protective group for a carboxyl group; R4 represents optionally substituted aryl; and R5 represents optionally substituted alkenyl, etc. The cephem compound is represented by general formula (II), wherein R?1, R2 and R3¿ are each as defined above; and R6 represents optionally substituted aryl.
摘要:
A process for the preparation of 3-halogenocephem derivatives of general formula (2), characterized by reacting an allenyl-β-lactam of general formula (1) with a halogenating agent in the presence of a cuprous or cupric salt: [wherein R1 is hydrogen, amino, or protected amino; R2 is hydrogen, halogeno, lower alkoxy, lower acyl, lower alkyl, lower alkyl having at least one group selected between hydroxyl and protected hydroxyl groups as a substituent, hydroxyl, or protected hydroxyl; R3 is hydrogen or a carboxyl-protecting group; R4 is a residue of an optionally substituted aromatic or nitrogeneous heteroaromatic compound; and n is an integer of 0 to 2] [wherein R?1, R2 and R3¿ are each as defined above; and X is halogeno].
摘要:
A process for producing a 3-substituted cephem compound from an allenyl-β-lactam compound which can readily be prepared from an inexpensive penicillin compound in a short reaction path. The process comprises reacting an allenyl-β-lactam compound with an organohalogen compound in the presence of an at least equimolar amount of a metal having a standard oxidation-reduction potential of -0.3 V/SCE or less and 0.0001 - 0.5 mol, per mole of the lactam, of a metallic compound having a standard oxidation-reduction potential higher than that of the above metal.
摘要:
A process for preparing an exo-methylenepenam compound represented by the formula (2) wherein cephem compound represented by the formula (1) is reduced with a metal having a standard oxidation-reduction potential of up to -0.3 (V/SCE) in an amount of at least one mole per mole of the cephem compound and with a metal compound having a higher standard oxidation reduction potential than the metal in an amount of 0.0001 to 10 moles per mole of the cephem compound to obtain the exo-methylenepenam compound wherein R is a hydrogen atom, amino or protected amino, R is a hydrogen atom, halogen atom, etc. R is a hydrogen atom or carboxylic acid protective group, X is a halogen atom, etc. wherein R , R and R are as defined above.d
摘要:
A process for the preparation of 3-alkoxymethylcephems, characterized by electrolytically oxidizing a 3-thiomethylcephem of general formula (I) (wherein R1 is hydrogen, amino or protected amino; R2 is optionally substituted aryl; and R3 is hydrogen or a carboxyl-protecting group) in the presence of a lower alcohol into a 3-alkoxymethylcephem of general formula (II) (wherein R1, R2 and R3 are each as defined above; and R4 is lower alkyl).
摘要:
A process for the production of a halogenated β-lactam compound represented by general formula (2) which comprises replacing the hydroxyl group of a halogenated β-lactam compound represented by general formula (1) with a halogen atom or a leaving group. Another process for the production of an exomethylene penam compound represented by general formula (5) which comprises reducing a halogenated β-lactam compound represented by general formula (2) with at least the equimolar amount of a metal having a standard oxidation-reduction potential of -0.3 (V/SCE) or below and 0.0001 to 10 times by mol as much a metal compound having a standard oxidation-reduction potential higher than that of the former metal, or employing the electrolytic reduction method.
摘要:
A process for producing an oxide having a higher degree of oxidation than an alcohol, characterized by depositing the alcohol compound and an oxidation catalyst on silica gel and oxidizing the compound with an oxidizing agent; and a process for producing an oxide having a higher degree of oxidation than an alcohol, characterized by depositing the alcohol compound on silica gel and then electrolytically oxidizing the compound.
摘要:
A process for the preparation of 3-alkenylcephem or 3-norcephem compounds represented by general formula (3), characterized by treating a 3-cephem compound of general formula (1) in a solvent with an alkenyl halide of general formula (2), a nickel catalyst, a metal having a standard redox potential of -0.3 (V/SCE) or below , and a compound of a metal having a standard redox potential higher than that of the above metal. Formula (1) (wherein R1 is hydrogen or the like; R2 is hydrogen or the like; R3 is hydrogen or a carboxyl-protecting group; and X is halogeno or the like). (Formula 2) R4-Y wherein R4 is optionally substituted 1-alkenyl; and Y is halogeno. Formula (3) (wherein R?1, R2, and R3¿ are each as defined above; and R5 is hydrogen or optionally substituted 1-alkenyl).