Syntheses of unsaturated polyesters containing betulinol moieties

Syntheses of polymers on the basis of betulinol ( 1 ), a pentacyclic triterpene glycol obtained from the birch bark, were investigated. Catalytic polyesterification of 1 with terephthaloyl chloride in various solvents gave only oligomers. Kinetic investigations indicated a very low activity of the hydroxyl groups of 1 . Chemical modification of betulinol revealed the possibility of a successful addition of its OH‐groups to anhydrides at high‐temperature. Unsaturated polyesters, based on maleic anhydride, betulinol and acyclic glycols, were synthesized and investigated. Samples of betulinol‐containing polyesters cured by copolymerization with styrene show improved water and chemical resistance.