Plastic materials are an ubiquitous part of modern life. Currently around 99% of plastics are produced from fossil resources, which, among other issues, contributes to their negative environmental impact. It has been largely recognized that a shift from fossil- to bio- and CO2-based materials can contribute to a more sustainable material sector. The aim of this thesis was the synthesis of polyesters based on the commercially available, biobased diol isosorbide. The high potential of this monomer as a renewable building block for polymer synthesis has been identified several decades ago. It can be synthesized from abundant glucose and has a rigid molecular structure, which imparts favourable material properties. Isosorbides utilization in polyester synthesis, however, remains challenging due to its unreactive secondary alcohol groups. In Chapter 1 of this thesis we provide an overview of past efforts to utilize isosorbide in polyester synthesis in the form of a literature review. In Chapter 2 we explore the synthesis of isosorbide copolyesters with CO2-derived oxalic acid and 1,4-butanediol. Chapter 3 contains the most interesting findings of this thesis. Therein we present a synthesis strategy to overcome the low reactivity of isosorbide in polyester synthesis by addition of an aryl alcohol during esterification. This leads to the in situ formation of reactive aryl esters which facilitate chain growth during polycondensation. In Chapter 4 we explore the depolymerization of abundant poly(ethylene terephthalate) to reactive diaryl ester monomers.