To efficiently obtain GVL from carbohydrate-rich biomass feedstock, a wide range of substrates must converge into the same product, and numerous undesired side reactions may hamper the process. The initial step is an acid mediated conversion of the biomass into its constituent polysaccharides (Figure ). Several types of polysaccharides are present in various biomass sources, including cellulose and hemicellulose from lignocellulose biomass, N-acetylglucosamine polymer from chitin, and amylose and amylopectin from starch, which must all be hydrolyzed to their monosaccharides, such as xylose, glucose, fructose, Nacetylglucosamine, and N-glucosamine. The catalytic system must also be able to withstand the selective dehydration of this pool of monosaccharides to furanics. To obtain levulinic acid (LA), furfural must be both hydrogenated and hydrolyzed, whereas HMF must be selectively only hydrolyzed. Finally, LA is hydrogenated to GVL (see scheme S1 for generally accepted detailed reaction pathways for all three types of carbohydrate-rich biomass). Figure . Selection of possible intermediates during the acid-and hydrogenation-mediated process of various biomass waste feedstock to GVL.