The fundamental principle of sustainability is that waste is not an old useless substance that needs to be disposed of, but is rather an important and multicomponent feedstock that can be exploited to produce new chemicals, materials and energy sources, thus re-entering the material cycle. Furthermore, the valorisation of waste must be done in a sustainable way, i.e. using en¬vironmental friendly technologies. These concepts have been the guidelines by which methods and chemical transformations have been conceived in this Thesis work. The Thesis is divided into five main sections. Chapter 1 introduces the reader to critical aspects of our society and the importance of a sustainable economic development through a Circular economy and the exploitation of biomass. In the four following chapters, the author explains the activity research carried out during the three years of PhD. Each section focuses on the development of novel green chemical technologies, based on the upgrading of platform chemicals derived from renewable feedstocks.