Abstract: Intermediates and a stepwise process for the conversion of ethyl 4-chloro-3R-hydroxybutyrate to optically active compounds of the formula ##STR1## wherein R is (C.sub.1 -C.sub.3)alkyl, phenyl or tolyl. The later compounds are in turn useful as an intermediate in the preparation of penem antibiotic 5R,6S-6-(1R-hydroxyethyl)-2-(1R-oxo-3S-thiolanylthio)-2-penem-3-carboxylic acic and corresponding pharmaceutically acceptable salts and esters.

Abstract: Process and intermediates for the conversion of 3R,4R-4-acetoxy-3-[1R-1-(silyloxy)ethyl]-2-azetidinones to antibacterial 5R,6S-6-(1R-1-hydroxyethyl)-2-(1-oxo-3-thiolanylthio)-2-penem-3-carboxylic acids, and the pharmaceutically-acceptable salts and pivaloyloxymethyl esters thereof.

Abstract: A novel process is described for preparation of biotin comprising preparation of substituted 3H, 5H-imidazo[1,5c]tetrahydro thiazoles by contacting the boron trifluoride adduct of an appropriate thiazoline with the metallic derivative of an ester enolate, reducing the ester, hydrolyzing the thiazolidine moiety and hydrolyzing or oxidizing the resultant compound. Intermediates obtained in the preparation of biotin by the above process and alternate procedures for preparing said intermediates are also presented. A novel process for preparation of d-biotin is also given.

Abstract: A process for the preparation of penicillanic acid 1,1-dioxide and esters thereof readily hydrolyzable in vivo, which comprises oxidation of a 6,6-dihalopenicillanic acid, or an ester thereof readily hydrolyzable in vivo, to the corresponding 6,6-dihalopenicillanic acid 1,1-dioxide or ester thereof, followed by dehalogenation (e.g. by hydrogenolysis). The 6,6-dihalopenicillanic acid 1,1-dioxides and esters thereof readily hydrolyzable in vivo are novel intermediates. Penicillanic acid 1,1-dioxide, and esters thereof readily hydrolyzable in vivo, are known compounds which are useful as beta-lactamase inhibitors and for enhancing the effectiveness of certain beta-lactam antibiotics (e.g. the penicillins) in the treatement of bacterial infections in mammals, particularly humans.

Abstract: Process and intermediates for the conversion of 3R,4R-4-acetoxy-3-[1R-1-(silyloxy)ethyl]-2-azetidinones to antibacterial 5R,6S-6-(1R-1-hydroxyethyl)-2-(1-oxo-3-thiolanylthio)-2-penem-3-carboxylic acids, and the pharmaceutically-acceptable salts and pivaloyloxymethyl esters thereof.

Abstract: Hypoglycemic 5-[1-(5,6,7,8-tetrahydro-2-napthyl-; 1,2,3,4-tetrahydro-6-quinolyl-; 2-indanyl-; and 2-indolyl)alkyl]thiazolidine-2,4-dione derivatives, pharmaceutically acceptable salts thereof, and a method for their use in the treatment of hyperglycemic mammals.

Abstract: A novel process is described for preparation of biotin comprising preparation of substituted 3H, 5H-imidazo[1, 5c]tetrahydro thiazoles by contacting the boron trifluoride adduct of an appropriate thiazoline with the metallic derivative of an ester enolate, reducing the ester, hydrolyzing the thiazolidine moiety and hydrolyzing or oxidizing the resultant compound. Intermediates obtained in the preparation of biotin by the above process and alternate procedures for preparing said intermediates are also presented. A novel process for preparation of d-biotin is also given.

Abstract: A process for the preparation of penicillanic acid 1,1-dioxide and esters thereof readily hydrolyzable in vivo, which comprises oxidation of a 6,6-dihalopenicillanic acid, or an ester thereof readily hydrolyzable in vivo, to the corresponding 6,6-dihalopenicillanic acid 1,1-dioxide or ester thereof, followed by dehalogenation (e.g. by hydrogenolysis). The 6,6-dihalopenicillanic acid 1,1-dioxides and esters thereof readily hydrolyzable in vivo are novel intermediates. Penicillanic acid 1,1-dioxide, and esters thereof readily hydrolyzable in vivo, are known compounds which are useful as beta-lactamase inhibitors and for enhancing the effectiveness of certain beta-lactam antibiotics (e.g. the penicillins) in the treatment of bacterial infections in mammals, particularly humans.

Abstract: Hypoglycemic 2,3-dihydro-5-benzo[b]furanyl-2,3-dihydro-5-benzo[b]thienyl-, 3,4-dihydro(2H)-6-benzopyranyl- and 6-thiochromanyl-thiazolidine-2,4-diones and pharmaceutically acceptable salts thereof, method for their use in treatment of hyperglycemic animals and pharmaceutical compositions containing them.

Abstract: A novel process is described for preparation of biotin comprising preparation of substituted 3H, 5H-imidazo[1,5c]tetrahydro thiazoles by contacting the boron trifluoride adduct of an appropriate thiazoline with the metallic derivative of an ester enolate, reducing the ester, hydrolyzing the thiazolidine moiety and hydrolyzing or oxidizing the resultant compound. Intermediates obtained in the preparation of biotin by the above process and alternate procedures for preparing said intermediates are also presented. A novel process for preparation of d-biotin is also given.

Abstract: A process for the preparation of a thieno-imidazole derivative, particularly descarboxybiotin, a useful intermediate for the preparation of d-biotin, which comprises reacting a thio-substituted intermediate, for example descarboxythiobiotin, with an epoxy compound in an alkanol solvent; and a process for the preparation of said intermediate by reacting a substituted imidazothiazole alcohol with anhydrous hydrogen fluoride.

Abstract: A novel process is described for preparation of biotin comprising preparation of substituted 3H, 5H-imidazo[1, 5c]tetrahydro thiazoles by contacting the boron triflouride adduct of an appropriate thiazoline with the metallic derivative of an ester enolate, reducing the ester, hydrolyzing the thiazolidine moiety and hydrolyzing or oxidizing the resultant compound. Intermediates obtained in the preparation of biotin by the above process and alternate procedures for preparing said intermediates are also presented. A novel process for preparation of d-biotin is also given.

Abstract: 6-alpha/beta-[(C.sub.1 -C.sub.4)Alkoxyaminomethyl and benzyloxyaminomethyl]penicillanic acid 1,1-dioxides, pharmaceutically acceptable salts thereof and conventional esters thereof hydrolyzable under physiological conditions, all of which are useful in medicine as beta-lactamase inhibitors; intermediates and processes therefor; and a process for the conversion of the present compounds to 6-alpha- and 6-beta-(aminomethyl)penicillanic acid 1,1-dioxides and derivatives.

Abstract: A novel process is described for preparation of biotin comprising preparation of substituted 3H, 5H-imidazo[1, 5c]tetrahydro thiazoles by contacting the boron trifluoride adduct of an appropriate thiazoline with the metallic derivative of an ester enolate, reducing the ester, hydrolyzing the thiazolidine moiety and hydrolyzing or oxidizing the resultant compound. Intermediates obtained in the preparation of biotin by the above process and alternate procedures for preparing said intermediates are also presented. A novel process for preparation of d-biotin is also given.

Abstract: 6-alpha/beta-[(C.sub.1 -C.sub.4)Alkoxyaminomethyl and benzyloxyaminomethyl]penicillanic acid 1,1-dioxides, pharmaceutically acceptable salts thereof and conventional esters thereof hydrolyzable under physiological conditions, all of which are useful in medicine as beta-lactamase inhibitors; intermediates and processes therefor; and a process for the conversion of the present compounds to 6-alpha- and 6-beta-(aminomethyl)penicillanic acid 1,1-dioxides and derivatives.

Abstract: A novel process is described for preparation of biotin comprising preparation of substituted 3H, 5H-imidazo[1, 5c]tetrahydro thiazoles by contacting the boron trifluoride adduct of an appropriate thiazoline with the metallic derivative of an ester enolate, reducing the ester, hydrolyzing the thiazolidine moiety and hydrolyzing or oxidizing the resultant compound. Intermediates obtained in the preparation of biotin by the above process and alternate procedures for preparing said intermediates are also presented. A novel process for preparation of d-biotin is also given.