Upcoming bio-refineries will be at the heart of the manufacture of future transportation fuels, chemicals and materials. A narrow number of platform molecules are envisioned to bridge nature's abundant polysaccharide feedstock to the production of added-value chemicals and intermediate building blocks. Such platform molecules are well-chosen to lie at the base of a large product assortment, while their formation should be straightforward from the refined biomass, practical and energy efficient, without unnecessary loss of carbon atoms. Lactic acid has been identified as one such high potential platform. Despite its established fermentation route, sustainability issueslike gypsum waste and cost factors due to multi-step purification and separation requirementswill arise as soon as the necessary orders of magnitude larger volumes are needed. Innovative production routes to lactic acid and its esters are therefore under development, converting sugars and glycerol in the presence of chemocatalysts. Moreover, catalysis is one of the fundamental routes to convert lactic acid into a range of useful chemicals in a platform approach. This contribution attempts a critical overview of all advances in the field of homogeneous and heterogeneous catalysis and recognises a great potential of some of these chemocatalytic approaches to produce and transform lactic acid as well as some other promising a-hydroxy acids. Broader contextLactic acid is one of the top biomass derived platform chemicals, with a promising role in future bio-reneries. A wide range of catalytic transformations of lactic acid are feasible leading to the selective production of green solvents, ne chemicals, commodity chemicals and fuel precursors. Even more appealing is its role as the precursor for biodegradable PLA (polylactic acid) polymers. These polyesters have the potential to replace fossil derived plastics in particular applications, and based on life cycle analyses, they have a more positive impact on the environment. PLA can also be used in vivo and in biomedical applications. The demand for PLA and green solvents is growing and stresses the current fermentative production of lactic acid, which suffers from up-scaling and environmental issues due to concerning waste co-generation and purication steps. Novel chemocatalytic routes are under development to obtain pure lactic acid or esters directly from sugar feedstock. These mainly heterogeneous catalytic processes have potential and could lie at the heart of an evolution in lactic acid research. Once lactic acid is available at competitive prices, its use as a feedstock in a platform approach could become commercially viable, thereby providing renewable and CO 2neutral alternatives for fossil derived chemicals.

In the reductive catalytic fractionation of lignocellulose, the choice of solvent significantly impacts the delignification efficiency, carbohydrate retention in the pulp and the macrostructure of the pulp.

Biodegradable and renewable polymers, such as polylactic acid, are benign alternatives for petrochemical-based plastics. Current production of polylactic acid via its key building block lactide, the cyclic dimer of lactic acid, is inefficient in terms of energy, time, and feedstock use. We present a direct zeolite-based catalytic process, which converts lactic acid into lactide. The shape-selective properties of zeolites are essential to attain record lactide yields, outperforming those of the current multistep process by avoiding both racemization and side-product formation. The highly productive process is strengthened by facile recovery and practical reactivation of the catalyst, which remains structurally fit during at least six consecutive reactions, and by the ease of solvent and side-product recycling.

The ideal support characteristics for immobilization of the Hoveyda–Grubbs 2 catalyst were defined in the metathesis of cyclooctene and the reaction mechanism to cyclic oligomers was unraveled.

Herein, we demonstrate a practical high yield preparation of large macrocyclic oligo(butadiene)s, preferably the C16 to C44 fraction, from commercial 1,4-polybutadiene by exploring intramolecular backbiting using a series of commercially available Ru catalysts.