The (controlled) free-radical copolymerization of maleic anhydride and styrene or derivatives thereof is often thought to provide nearly perfect alternating copolymers. Here, the RAFT copolymerization of electron-rich styrene derivatives with maleic anhydride is reported. This copolymerization shows distinct penultimate effects, resulting in polymers with increased incorporation of styrene monomers, that is, where a tendency toward periodic (S-S-MA) copolymers exists. This work could be a first step towards periodic copolymers based on maleic anhydride and styrene derivatives. (C) 2016 Wiley Periodicals, Inc.