Abstract: 6-Amino-spiro[penam-2,4'-piperidine]-3-carboxylic acid derivatives having the formula ##STR1## wherein R is a methyl, phenyl or benzyl radical, Z.sub.1 is a hydrogen atom and Z.sub.2 is a radical selected from those known from penicillin chemistry and is preferably a 2-phenylacetyl, 2-amino-2-phenylacetyl, 5-methyl-3-phenyl-4-isoxazolecarbonyl or 2,6-dimethoxybenzoyl radical, or Z.sub.1 and Z.sub.2 together represent a bivalent radical Z.sub.3 and preferably a (hexahydro-1H-azepin-1-yl)methylene radical, as well as the pharmaceutically acceptable non-toxic salts thereof and process for preparing the same.These compounds have valuable antibacterial properties and are useful as therapeutic agents in the treatment of infectious diseases caused by Gram-positive and Gram-negative bacteria.

Abstract: 6-Amino-spiro[penam-2,4'-piperidine]-3-carboxylic acids, salts and esters thereof of the formula ##STR1## wherein R.sub.1 is hydrogen, benzyl or an alkali metal or ammonium ion and R.sub.2 is methyl, phenyl or benzyl and process for preparing the same.These compounds are useful as intermediates in the synthesis of a new group of antibiotics having properties similar to penicillins, besides own antibiotic activity with a broad antibacterial spectrum. Therefore, they are useful as antibacterials agents and as therapeutic agents for humans and for animals in the treatment of infectious diseases caused by Gram-positive and Gram-negative bacteria.

Abstract: Amino-spiro[oxa(or thia)cycloalkane-penam]-carboxylic acid derivatives having the formula ##STR1## WHEREIN X is a sulfur or oxygen atom or the sulfinyl group, n is 1 or 2, m is 1 or 2, R.sub.1 is hydrogen, R.sub.2 is one of the radicals known in the chemistry of the penicillins, preferably 2-phenylacetyl, 2-amino-2-phenylacetyl, 5-methyl-3-phenyl-4-isoxazolecarbonyl or 2,6-dimethoxybenzoyl, or R.sub.1 and R.sub.2 together represent a bivalent radical R.sub.3, preferably (hexahydro-1H-azepin-1-yl)methylene and their therapeutically acceptable non-toxic salts and process for preparing the same.These compounds have valuable antibacterial properties and are useful as therapeutic agents in the treatment of infectious diseases caused by Gram-positive and Gram-negative bacteria.

Abstract: Amino-spiro[oxa(or thia)cycloalkane-penam]-carboxylic acid, a salt or an ester thereof, of the formula ##STR1## wherein Z is a hydrogen or an alkali metal atom, or a group protecting the carboxylic function, X is a sulfur or oxygen atom, n is 1 or 2, m is 1 or 2, and process of preparing the same.These compounds are useful as intermediates in the synthesis of a new group of antibiotics having properties similar to penicillins, besides own antibiotic activity with a broad antibacterial spectrum.