The central objective of this project is to provide new fundamental insights into the reactivity of beta-lactams and to apply this knowledge for the construction of biologically relevant target structures.From a synthetic chemistry point of view, the generation of 2-oxoazetidin-4-yl anions via deprotonation of appropriately substituted beta-lactams is contemplated, followed by C4 alkylation upon treatment with dihaloalkanes and cyclization of theresulting 4-(omega-haloalkyl)-beta-lactams toward novel C-, N- and spiro-fused beta-lactams