Conversion of Glycerol to 1,3-Propanediol via Selective Dehydroxylation

This paper presents a new approach to the production of 1,3-propanediol from glycerol via selective dehydroxylation. The idea is to selectively transform the middle hydroxyl group of glycerol into a tosyloxyl group and then remove the transformed group by catalytic hydrogenolysis. With this new approach, the conversion of glycerol to 1,3-propanediol is completed in three steps, namely, acetalization, tosylation, and detosyloxylation. All of these steps are experimentally examined in the current work to verify the feasibility of the new conversion approach. Before this work, the hydrogenolysis of tosylates had never been reported to have been performed catalytically with H2 as the reducing reagent. This work shows that this reaction can be effected, provided that the tosylate of concern contains a hydroxyl group next to its tosyloxyl group. The mechanism of this reaction is also established.