kahest identsest alkeenist tsüklobutaani moodustumise fotokeemiline protsess, s.t elektron-ergastatud alkeeni fototsükloliitumine põhiolekus alkeeniga
photochemical process leading to the formation of a cyclobutane from two identical alkenes, i.e., from the photocycloaddition of an electronically excited alkene to a ground-state alkene
