Valnemulin is a semi-synthetic pleuromutilin prepared by sequential reaction of pleuromutilin tosylate with 2-amino-1,1-dimethylethylthiol, coupling the free amine with a protected valine and then deprotection to provide the final product. Valnemulin is a broad spectrum antibiotic used to control gastrointestinal infections in animals and shows no cross resistance to other antibiotic classes.