(473a) Selective Dehydration of Polyols to Commodity Chemicals

Synthesis of commodity chemicals from biorenewable sources is an important component of a
sustainable society. Due to the very different chemical nature of bio-based feedstocks, a fundamental
understanding of the chemical conversion of bio-derived molecules, and the mechanisms thereof, will
be necessary for production of biorenewable chemicals. One reaction of interest for biorenewable
chemicals is the selective removal of oxygen from polyols. In this presentation, the dehydration of
1,2,ω triols and 1,3,ω triols will be discussed. The dehydration reactions were carried out by pulsing
solutions of a given triol through a gas chromatogram (GC) liner packed with amorphous silica-
alumina, and observing selectivity changes as a function of material introduced versus catalyst weight.
The role of acid site density and deactivation of the catalyst will be discussed in the presentation, along
with the role in hydroxyl group location on the triol and selectivity toward dehydration of primary
versus secondary alcohols. Further, the role of hydroxyl group location and carbon chain length on
selectivity to either the elimination of a hydroxyl or the formation of a furan, pyran, or oxepan ring will
also be discussed in this presentation. Overall, a set of reactivity rules, including observed exceptions to
the traditionally expected results for a dehydration reaction, will be proposed.