This dissertatation is dedicated to the development of methods aimed at the preparation of 7-aklylidenecephem un 6-alkylidenepenam derivatives and to the investigation of their chemical and biological properties. As a result of the perfomed investigations new cephalosporin and penicillin structural analogues there were prepared. Conformation of the substituents for the synthesized compounds was realized using 1H-1H NOESY spectroscopy. The obtained cephem and penam derivatives were subjected to biological screening, which included evaluation of their antitumor activity in vitro, their NO radical generating and lactamase inhibiting properties.