Takasago International Corporation

Shunichi Murahashi

Hidenori Kumobayashi

Takao Saito

A process for preparing a 4-acyloxyazetidinone or a derivative thereof represented by formula (IV): ##STR1## wherein R.sup.1 represents a hydrogen atom, a lower alkyl group, a hydroxyethyl group, or a protected hydroxyethyl group; R.sup.3 represents an alkyl group having from 1 to 10 carbon atoms which may be substituted with a halogen atom, a cyano group, a lower alkoxy group or a phenyl group, or a substituted or unsubstituted phenyl group, provided that the .alpha.-positioned carbon atom of said alkyl group should not have more than two halogen atoms; and R.sup.4 represents a hydrogen atom, a lower alkyl group, or a lower alkoxycarbonyl group, which is useful as an intermediate for penem antibiotics is disclosed, comprising reacting azetidinone or a derivative thereof represented by formula (II): ##STR2## wherein R.sup.1 is as defined above, and R.sup.2 represents a hydrogen atom, a lower alkyl group, a lower alkoxycarbonyl group, or a carboxyl group, with a carboxylic acid represented by formula (III):

Substituted acetoxyazetidinone derivatives and process for preparing

A process for preparing a 4-acyloxyazetidinone or a derivative thereof represented by formula (IV): ##STR1## wherein R.sup.1 represents a hydrogen atom, a lower alkyl group, a hydroxyethyl group, or a protected hydroxyethyl group; R.sup.3 represents an alkyl group having from 1 to 10 carbon atoms which may be substituted with a halogen atom, a cyano group, a lower alkoxy group or a phenyl group, or a substituted or unsubstituted phenyl group, provided that the .alpha.-positioned carbon atom of said alkyl group should not have more than two halogen atoms; and R.sup.4 represents a hydrogen atom, a lower alkyl group, or a lower alkoxycarbonyl group, which is useful as an intermediate for penera antibiotics is disclosed, comprising reacting azetidinone or a derivative thereof represented by formula (II): ##STR2## wherein R.sup.1 is as defined above, and R.sup.2 represents a hydrogen atom, a lower alkyl group, a lower alkoxycarbonyl group, or a carboxyl group, with a carboxylic acid represented by formula (III):

Ru catalyzed acyloxylation process for preparing 4-acyloxyazetidinone

A process for producing an .alpha.-hydroxyketone represented by formula (I): ##STR1## wherein R.sup.1 represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or an alkoxycarbonyl group; and R.sup.2 and R.sup.3 each represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aralkyl group, provided that they do not simultaneously represent a hydrogen atom; or a pair of R.sup.1 and R.sup.2, a pair of R.sup.1 and R.sup.3, or a pair of R.sup.2 and R.sup.3 is taken together to form a ring; and the pair of R.sup.1 and R.sup.2 and the pair of R.sup.2 and R.sup.3 may form a ring simultaneously, is disclosed, comprising reacting a compound represented by formula (II): ##STR2## wherein R.sup.1, R.sup.2, and R.sup.3 are as defined above, with an oxidizing agent in the presence of a ruthenium compound and water. .alpha.-Hydroxyketones useful as physiologically active substances are produced with good selectivity and in high yield.

Process for producing .alpha.-hydroxyketones

A process for producing a 4-acetoxyazetidinone represented by formula (I): ##STR1## wherein Z represents a hydrogen atom, a lower alkyl group, or a protected or unprotected hydroxyethyl group; and W represents a hydrogen atom, a lower alkyl group, or a group of --COOR.sup.1, wherein R.sup.1 represents a lower alkyl group, is disclosed, which comprises reacting an azetidinone represented by formula (II): ##STR2## wherein Z is as defined above; and Y represents a hydrogen atom, carboxyl group, a lower alkyl group, or a group of --COOR.sup.1, wherein R.sup.1 represents a lower alkyl group, with acetic acid and an oxidizing agent in the presence of, as a catalyst, an anhydrous or hydrous osmium compound represented by OsX.sub.3, wherein X represents a chlorine atom, a bromine atom, or an iodine atom.

Growing community of inventors

Osaka, Japan

Shunichi Murahashi