In order to get a clearer view on the active geometry of anti-invasive chalcones, we have prepared a number of isoxazoles and related substances as conformationally restrained mimics of 1, 3-diarylpropenones, and also of (Z)-stilbenes. In vitro anti-invasive activity data for 3, 5-isoxazoles and 4, 5-isoxazoles, together with an in silico geometrical comparison, point towards an active conformation for chalcones more resembling their s-trans ...