摘要:
A process for producing cyclohexylazetidinone expressed by the formula(IV) comprises condensing the magnesium enolate compound expressed by the formula (II) with acyloxyazetidinone expressed by the formula (III), wherein Me is a methyl group; R.sup.1 is a hydroxyl-protecting group, R.sup.2 is an acyl group, and X is a halogen atom. ##STR1##
摘要:
A process for producing an optically active cyclohexanol derivative represented by formula (I): ##STR1## wherein R.sup.1 represents an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, or a protected hydroxyl group, comprising asymmetrically hydrogenating a cyclohexanone derivative in the presence of a catalyst system composed of a transition metal compound (e.g., transition metal complex), a base (e.g., KOH), and a nitrogen compound (e.g., an amine compound).
摘要:
Disclosed is a process for the preparation of a 4-substituted azetidinone derivative, which comprises reacting an azetidinone derivative and an amide compound in the presence of a magnesium compound such as those represented by the following formulas (II): and (IV): represented by the following formula (III): MgR5R6 (III) wherein R5 represents a C1-12 alkyl group, a C2-5 alkenyl group, a 5- to 8-membered alicyclic group which may be substituted by a lower C1-4 alkyl group, a phenyl group which may be substituted by a lower C1-4 alkyl group, a lower C1-4 alkoxy group or a halogen atom or a benzyl group which may be substituted by a lower C1-4 alkyl group, a lower C1-4 alkoxy group or a halogen atom, and R6 represents a halogen atom, a methanesulfonyloxy group, a benzenesulfonyloxy group, a p-toluenesulfonyloxy group, a trifluoromethanesulfonyloxy group, an acetoxy group which may be substituted by a halogen atom or a cyano group or an OR7 group (R7 representing a lower C1-4 alkyl group, a substituted or unsubstituted phenyl group or a substituted or unsubstituted benzyl group). The process provides an industrially excellent process for the preparation of a 4-substituted azetidinone derivative which permits the selective preparation of an intermediate for the synthesis of a carbapenem antibacterial agent having a desired 1-&bgr;′ configuration.
摘要:
To prepare the compound (1'R,3S)-3-(1'-tri-substituted silyloxyethyl)azetidin-2-one, (2S,3R)-2-aminomethyl-3-hydroxybutyric acid is reacted with an alcohol in the presence of at least one compound chosen from the group consisting of thionyl chloride, hydrogen chloride and p-toluene sulfonic acid, thereby obtaining a salt of the corresponding ester. The salt is reacted with a tri-substituted silane in the presence of a metallic catalyst, thereby protecting the hydroxy group of the ester and then reacted with a base, thereby obtaining an ester of (2S,3R)-2-aminomethyl-3-(tri-substituted silyloxy)butyric acid. Subsequently, the ester is transformed into lactam in the presence of a Grignard reagent or a metal amide, thereby obtaining (1'R,3S)-3-(1'-tri-substituted silyloxyethyl)azetidin-2-one. This compound provides a useful base for preparing .beta.-lactam type antimicrobial agents such as carbapenem type agents.
摘要:
This invention provides a novel process for producing optically active 3-hydroxy-&ggr;-butyrolactone in a short step, which is superior economically and in efficiency and industrially suitable by using a starting material which is inexpensive and easily available and reagents easy to handle. This invention relates to a process for producing optically active 3-hydroxy-&ggr;-butyrolactone represented by formula I: wherein the symbol * means an asymmetric carbon atom, which comprises hydrogenating an optically active 4-substituted oxy-3-hydroxybutyrate represented by formula II: wherein R1 represents a C1-4 lower alkyl group, R2 represents a protective group for a hydroxyl group deprotected by hydrogenation with a heterogeneous hydrogenation catalyst, and the symbol * has the same meaning as defined above, in the presence of a heterogeneous hydrogenation catalyst and an acidic substance followed by deprotection and simultaneous ring closure thereof.
摘要:
Disclosed is a process for preparing an optically active oxazolidinone derivative comprising allowing hydrazine to react on an optically active ester having a hydroxyl group at the 3-position which is represented by formula (II): wherein R1 represents a lower alkyl group having 1 to 4 carbon atoms, a phenyl group, a methoxymethyl group, a benzyloxymethyl group, a benzyloxycarbonylaminomethyl group which may have a substituent or substituents on the benzene ring thereof, an acylaminomethyl group having 3 to 10 carbon atoms, or an alkyloxycarbonylaminomethyl group having 3 to 6 carbon atoms; R2 and R3, which may be the same or different, each represent a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, a phenyl group, an acetylaminomethyl group, a benzoylaminomethyl group, or a benzyl group; and * indicates an asymmetric carbon atom, and subjecting the resulting hydrazide to Curtius rearrangement.
摘要翻译:公开了一种制备光学活性恶唑烷酮衍生物的方法,其包括使肼在由式(II)表示的3-位具有羟基的光学活性酯上反应:其中R1表示具有1-4个碳原子的低级烷基 碳原子,苯基,甲氧基甲基,苄氧基甲基,苯环上可以具有取代基的苄氧羰基氨基甲基,碳原子数3〜10的酰氨基甲基或碳原子数3〜6的烷氧基羰基氨基甲基 原子 R 2和R 3可以相同或不同,分别表示氢原子,碳原子数1〜4的低级烷基,苯基,乙酰氨基甲基,苯甲酰基氨基甲基或苄基。 和*表示不对称碳原子,并将所得酰肼进行柯氏重排。
摘要:
A process for preparing (1'R,3S)-3-(1'-hydroxyethyl)-azetidin-2-one or a derivative thereof represented by formula (I): ##STR1## wherein R.sup.1 represents a hydrogen atom or a hydroxyl-protective group, is disclosed, comprising reacting (2S,3R)-2-aminomethyl-3-hydroxybutyric acid or a derivative thereof represented by formula (II): ##STR2## wherein R.sup.1 is as defined above, with a sulfenamide represented by formula (III): ##STR3## wherein R.sup.2 represents ##STR4## and R.sup.3 and R.sup.4 each represent a hydrogen atom or a cyclic or acyclic hydrocarbon group, provided that they do not simultaneously represent a hydrogen atom, or R.sup.3 and R.sup.4 are taken together with the adjacent nitrogen atom to form a heterocyclic group, and triphenylphosphine. The reaction yield is high, and the sulfenamide (III) used as a lactamization reagent is cheap and can be recovered after the reaction.
摘要:
A 4-(1,1-dialkoxycarbonylalkyl )azetidin-2-one derivative represented by formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are identical or different and each represents an alkyl group, an alkenyl group, or an aralkyl group, R.sup.3 represents a lower alkyl group, R.sup.4 represents a hydrogen atom or a hydroxyl-protective group, and R.sup.5 represents a hydrogen atom or an amino-protective group, and a process for producing a 4-(1-carboxyalkyl)azetidin-2-one derivative represented by formula (II) useful as an intermediate for 1.beta.-alkylcarbapenem-type antibacterials: ##STR2## wherein R.sup.3 represents a lower alkyl group and R.sup.4 represents a hydrogen atom or a hydroxyl-protective group, which comprises de-esterifying and decarboxylating the derivative represented by formula (I), and in the case where an amino-protective group is present in the derivative of formula (I), eliminating the protective group from the derivative, are disclosed.
摘要:
A process for preferentially producing a 4-(1-carboxyalkyl) azetidin-2-one derivative represented by formula (II.beta.): ##STR1## wherein R.sup.3 represents a lower alkyl group and R.sup.4 represents a hydrogen atom or a hydroxy-protective group, which involves deesterifying and decarboxylating a 4-(1,1-dialkoxycarbonylalkyl) azetidin-2-one derivative represented by formula (I): ##STR2## wherein R.sup.1 and R.sup.2 are identical or different and each represents an alkyl group, an alkenyl group, or an aralkyl group, R.sup.3 and R.sup.4 each has the meaning as defined above, and R.sup.5 represents an amino-protective group, and after that, eliminating the amino-protective group from the derivative, where the 4-(1-carboxyalkyl)azetidin-2-one derivative of formula (II.beta.) is present in an amount of at least 61% by mol of all 4-(1-carboxyalkyl)azetidin-2-one derivatives produced.
摘要:
There is provided an information processing apparatus including a communication unit which communicates with a distribution server that contains content data for streaming delivery, a buffer unit which temporarily stores stream data obtained from the distribution server, a storage unit which stores an inserting content, a reproduction unit which reproduces the content inserted by the storage unit, and a control unit which measures a bandwidth of the network, determines whether it is possible to reproduce until the end of a next chapter defined by a chapter point set in the content based on a buffer volume of the buffer unit and the bandwidth, and when determined it is impossible, switches the content to be produced by the reproduction unit to the inserting content.