Use of readily available monomers in the synthesis of vinyl copolymers with optical activity arising from the configuration of stereogenic carbon atoms in the main chain

Abstract

The present work was aimed at synthesising vinyl copolymers with optical activity arising only from the configuration of the stereogenic carbon atoms in the main chain. By copolymerising optically active diesters of fumaric acid with styrene, backbones with a composition of ∼ 2:1 (styrene:fumarate) were obtained displaying strongly negative optical rotations. Cleavage of the optically active alcohol auxiliaries from the side chain yielded corresponding styrene–fumaric acid copolymers displaying a small positive optical rotation. Thus, propagation occurs in these copolymerisations with asymmetric induction to generate a main chain with its own intrinsic asymmetry and corresponding optical activity. The mechanism of the induction is discussed. Corresponding copolymers involving isobutyl vinyl ether (IBVE) or dec-1-ene were synthetically more problematical and this is also discussed.