Beta-lactam compounds, processes for their production, compositions containing them and intermediates of use in their preparation

beta -Lactam compounds of the formulae are disclosed in which R represents a carboxyl or esterified carboxyl group and X represents a sulphonyloxy group. Processes for preparing the compounds and intermediates of use in their preparation are also disclosed. The compounds are of value in the preparation of further beta -lactam compounds, for example of formulae in which R is a carboxyl or esterified carboxyl group, and R is the residue of a sulphur nucleophile. Compounds of formula (I) are also disclosed, together with processes for their preparation, pharmaceutical compositions containing them and intermediates of use in their preparation. The compounds of formula (I) are of value as antibiotics or as beta -lactamase inhibitors.