CC BY-NC 3.0 UnportedDell'Acqua, AndreaStadler, Bernhard M.Kirchhecker, SarahTin, Sergeyde Vries, Johannes G.2021-11-112021-11-112020https://oa.tib.eu/renate/handle/123456789/7263https://doi.org/10.34657/6310Bio-based levulinic acid is easily ring-closed to α-angelica lactone (α-AL). α-AL can be isomerized to the conjugated β-AL under the influence of base, but since this is an equilibrium mixture it is very hard to devise a scalable process that would give pure β-AL. This problem was circumvented by distilling the equilibrium mixture to obtain a 90 : 10 mixture of β-and α-AL in 88% yield. This mixture was used for Diels-Alder reactions on 3 terpenes and on cyclopentadiene in up to 100 g scale. The latter DA adduct was subjected to a ROMP reaction catalysed by the Grubbs II catalyst. The resulting polymer has some similarities to poly-norbornene but is more polar. The polymer can be processed into films with very good transparency. © The Royal Society of Chemistry.enghttps://creativecommons.org/licenses/by-nc/3.0/540EstersPolymer filmsBio-basedCyclopentadienesDiels-Alder reactionEquilibrium mixturesLevulinic acidNorbornenesScalable synthesisMixturesArticle