Benzene derivatives, which contain two, three or four photoreactive functionalities, such as vinyl, styryl or cinnamoyl groups, can undergo multiple [2p+2p] photocycloaddition reactions on irradiation. The resulting dimers have the substructure of [2.2]- or [4.4]cyclophanes, whose bridges contain cyclobutane rings as distinctive features. Among the variety of synthetic approaches to cyclophanes, this photochemical method provides an easy and versatile preparation mode for many different systems.