Abstract: A process for preparing optically active alcoholic compounds wherein a carbonyl compound is assymmetrically reduced in an economical and practical manner. The process comprises treating a prochiral carbonyl compound represented by the general formula (1) with an optically active organoaluminum compound represented by the general formula (2) to conduct asymmetric reduction, thereby preparing an optically active alcoholic compound represented by the general formula (3).

Abstract: The present invention provides a process for reducing carbonyl compounds to hydroxy compounds, in particular stereoselectively reducing .alpha.-aminohaloketone derivatives, under mild conditions in an easy and simple manner, which comprises reacting a carbonyl compound of the general formula (1) with an organoaluminum compound of the general formula (4) to provide the corresponding alcohol compound of the general formula (5).

Abstract: It is an object of the present invention to provide a process for producing an pyrrolidine derivative of general formula (2) or a salt thereof in a simple and economical manner and with good productivity and high yields.The present invention consists in a process for producing a pyrrolidine derivative of the general formula (2) or a salt thereof which comprises subjecting a compound of the general formula (1) to hydrogenolysis using a metal catalyst in the presence of at least one protic acid selected from the group consisting of hydrochloric acid, sulfuric acid, phosphoric acid, p-toluenesulfonic acid, methanesulfonic acid, acetic acid, n-butyric acid, trifluoroacetic acid and oxalic acid. ##STR1## R represents a 1-cyano-1,1-diphenylmethyl, 1-carbamoyl-1,1-diphenylmethyl, n-butyryloxy, methanesulfonyloxy or p-toluenesulfonyloxy group.

Abstract: There is described a process for preparing 3-(2-thienylthio)butyric acid by converting a compound having the formula (III): ##STR1## wherein R is a straight chain or branched C.sub.1 to C.sub.4 alkyl group, whereby the production of 3-(3-thienylthio)butyric acid as a by-product which is the position isomer can be controlled to at most 0.1 mol %. 3-(2-Thienylthio)butyric acid is a useful compound as an intermediate for a medicinal compound.

Abstract: A process for efficiently producing (S,S)-2-alkoxycyclohexanols in a single step by using (.+-.)-trans-2-alkoxycyclohexanols which are inexpensive and can be easily obtained. The process comprises treating a (.+-.)-trans-2-alkoxycyclohexanol with a hydrolase originating in a microorganism and being capable of esterifying stereospecifically the R-isomer in the presence of an acyl donor under such conditions that no hydrolysis occurs substantially to thereby give (S,S)-2-alkoxycyclohexanols and (R,R)-2-alkoxycyclohexanol carboxylate and then taking up the (S,S)-2-alkoxycyclohexanols.

Abstract: There is described a process for preparing 3-(2-thienylthio)butyric acid by converting a compound having the formula (III): ##STR1## wherein R is a straight chain or branched C.sub.1 to C.sub.4 alkyl group, whereby the production of 3-(3-thienylthio)butyric acid as a by-product which is the position isomer can be controlled to at most 0.1 mol %. 3-(2-Thienylthio)butyric acid is a useful compound as an intermediate for a medicinal compound.

Abstract: A process for preparing an enol silyl ether compound from a diazoacetoacetic acid ester having the general formula (IV): ##STR1## wherein R.sup.1 is a lower alkyl group having 1 to 6 carbon atoms, phenyl group, a substituted phenyl group, an aralkyl group or allyl group, and R.sup.2, R.sup.3 and R.sup.4 are the same or mutually different and each is a lower alkyl group having 1 to 6 carbon atoms, which comprises reacting a diazoacetoacetic acid ester having the general formula (I): ##STR2## wherein R.sup.1 is the same as defined above, with a trialkylsilyl chloride having the general formula (II): ##STR3## wherein R.sup.2, R.sup.3 and R.sup.4 are the same as defined above, in an inert solvent in the presence of an organic base and an alkali halide having the general formula (III):MX (III)wherein M is an alkaline metal and X is bromine atom or iodine atom. The desired compound is useful as an intermediate for synthesis of carbapenem .beta.-lactam antibiotics.

Abstract: The present invention relates to .beta.-lactam compound having the formula (I): ##STR1## wherein R.sup.1 is a trialkylsilyl group, dimethyl-1,1,2-trimethylpropylsilyl group, acetyl group, benzyloxycarbonyl group, O-nitrobenzyloxycarbonyl group, p-nitrobenzyloxycarbonyl group or t-butyl group, R.sup.2, R.sup.3 and R.sup.4 are a member selected from the group consisting of a lower alkyl group having 1 to 6 carbon atoms, phenyl group and an aralkyl group and a process for preparing the compound which comprises reacting enolsilylethers having the formula (III): ##STR2## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as above, with chlorosulfonylisocyanate and then reducing the obtained product. The .beta.-lactam compound of the present invention is a useful intermediate for preparing carbapenem .beta.-lactam compound.

Abstract: A process for preparing a 4-acetoxy-3-hydroxyethylazetidin-2-one derivative having the formula (II): ##STR1## wherein R.sup.1 is a protective group for the hydroxyl group, which comprises reacting a .beta.-lactam compound having the formula (I): ##STR2## wherein R.sup.1 is as defined above, and R.sup.2, R.sup.3 and R.sup.4 are a lower alkyl group having 1 to 6 carbon atoms, phenyl group or an aralkyl group, with acetic anhydride in an organic solvent in the presence of a low concentration of a substituted pyridine. According to the present invention, there can be obtained 4-acetoxy-3-hydroxyethylazetidin-2-one derivatives, which are useful intermediates for preparing carbapenem .beta.-lactam antibiotics.

Abstract: A process for preparing a 4-acetoxy-3-hydroxyethylazetidin-2-one derivative having the formula (II): ##STR1## wherein R.sup.1 is a protective group for the hydroxyl group, which comprises reactig a .beta.-lactam compound having the formula (I): ##STR2## wherein R.sup.1 is as difined above and R.sup.2, R.sup.3 and R.sup.4 are the same or different and each is a lower alkyl group having 1 to 4 carbon atoms or an aralkyl group, with acetic anhydride in the presence of a base and a catalyst selected from the group consisting of an organic strong acid, a mineral acid, a Lewis acid, a halogenated acyl compound having the formula (IV):R.sup.8 --CO--X (IV)wherein R.sup.8 is an alkyl group, an aralkyl group or phenyl group and X is a halogen atom, a halogenated sulfonyl compound having the formula (V):R.sup.9 --SO.sub.2 --X (V)wherein R.sup.9 is an alkyl group, an aralkyl group or phenyl group and X is a halogen atom, and a compound having the formula (VI):(R.sup.10).sub.4-n --Si(X').sub.n (VI)wherein R.sup.

Abstract: A process for preparing a 4-acetoxy-3-hydroxyethylazetidin-2-one derivative having the formula (II): ##STR1## wherein R.sup.1 is a protective group for the hydroxyl group, which comprises reacting a .beta.-lactam compound having the formula (I): ##STR2## wherein R.sup.1 is as defined above, R.sup.2, R.sup.3 and R.sup.4 are a lower alkyl group having 1 to 6 carbon atoms, phenyl group or an aralkyl group and R is a protective group for N, with acetic anhydride in an organic solvent in the presence of a base, and removing the protective group for N.4-Acetoxy-3-hydroxyethylazetidin-2-one derivatives are useful intermediates for preparing carbapenem .beta.-lactam antibiotics such as thienamycin and penem .alpha.-lactam antibiotics.

Abstract: The present invention relates to .beta.-lactam compound having the formula (I): ##STR1## wherein R.sup.1 is a trialkylsilyl group, dimethyl-1,1,2-trimethylpropylsilyl group, acetyl group, benzyloxycarbonyl group, O-nitrobenzyloxycarbonyl group, p-nitrobenzyloxycarbonyl group or t-butyl group, R.sup.2, R.sup.3 and R.sup.4 are a member selected from the group consisting of a lower alkyl group having 1 to 6 carbon atoms, phenyl group and an aralkyl group and a process for preparing the compound which comprises reacting enolsilylethers having the formula (III): ##STR2## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as above, with chlorosulfonylisocyanate and then reducing the obtained product. The .beta.-lactam compound of the present invention is a useful intermediate for preparing carbapenem .beta.-lactam compound.

Abstract: A process is disclosed wherein an optically active .beta.-mercaptoalkanoic acid represented by formula (I): ##STR1## wherein R.sub.1 is lower alkyl having from 1 to 4 carbon atoms, is prepared by(1) reacting an optically active .beta.-hydroxyalkanoic acid represented by formula (II): ##STR2## wherein R.sub.1 is the same as defined above, with a halogenating reagent to prepare an optically active .beta.-haloalkanoyl halide represented by formula (III): ##STR3## wherein X is halogen and R.sub.1 is the same as defined above; (2) reacting the .beta.-haloalkanoyl halide with water or an aqueous alkaline solution to prepare an optically active .beta.-haloalkanoic acid represented by formula (IV): ##STR4## wherein X and R.sub.1 are each the same as defined above, or a salt thereof, respectively; and(3) reacting the .beta.

Abstract: A process is disclosed wherein an optically active N-mercaptoalkanoylamino acid is prepared by(1) reacting an optically active .beta.-hydroxyalkanoic acid, with a halogenating reagent to prepare an optically active .beta.-haloalkanoyl halide(2) reacting the .beta.-haloalkanoyl halide with an amino acid to produce an optically active N-.beta.-haloalkanoylamino acid and(3) reacting the N-.beta.-haloalkanoylamino acid with a reagent capable of converting the halogen into the thiol group, the configuration of the formulas (II), (III), (IV), (V), and (VI) being retained in all the optically active compounds throughout the process to prepare the compound represented by formula (I). The product of the present invention, for example, N-(3-mercapto-2-D-methylpropanoyl)-L-proline inhibits the enzymatic conversion of angiotensin I into angiotensin II and therefore is useful for relieving angiotensin-related hypertension.