Catalytic Synthesis of Oxazolidinones from a Chitin-Derived Sugar Alcohol

Abstract

Abstract Chitin is an abundant marine biomass that contains nitrogen atoms in its monomer units. Therefore, it is an attractive feedstock for the production of renewable organonitrogen compounds. The hydrolytic hydrogenation of chitin produces 2-acetamide-2-deoxysorbitol (ADS), which is a potential platform chemical in chitin-based biorefinery. In this work, we report the catalytic conversion of ADS to oxazolidinones named 2,3-OX and 1,2-OX. Of the two isomers, 2,3-OX possesses specific chirality suited for the application of antibiotic agents, naturally derived from ADS. This work demonstrates that a ubiquitous base catalyst, KHCO3, selectively gives 2,3-OX in 84% yield, 12 times more preferential than 1,2-OX under kinetic control. DFT calculations show that inner-molecular hydrogen bonds formed in the transition states specifically reduce the energy barrier for the 2,3-OX formation, thus giving this isomer selectively. We also found that the addition of boron compounds slightly shifts the selectivity towards 1,2-OX.