2020 Stephen S. Chang Award Lecture

2020 Stephen S. Chang Award Lecture presented by Dr. Dharma R. Kodali. The presentation will be livestreamed at https://annualmeeting.aocs.org/watch-the-livestream


Chemical synthesis as a tool to create value in lipid related products

This presentation describes how we used chemical modifications as a tool over the years to provide value through a fundamental understanding of the structure-property-functionality of glycerol ester derivatives and in creating new products. Initially, pure stereospecific glycerol derivatives were synthesized, and the fundamental aspects of structure-property correlations were studied. Various mono-, di- and tri-acyl-sn-glycerols were synthesized by protecting and deprotecting hydroxyl function with benzyl, trityl and isopropylidene groups. The synthesis of pure partial glycerol esters presented a challenge due to acyl migration. The driving force for the acyl migration of partial glycerol esters is the efficiency of the nucleophilic attack by the adjacent hydroxyl oxygen on the carbonyl carbon leading to the formation of an isomer through an orthoester intermediate. The acyl migration was more facile in liquid form and at higher temperatures. By employing various synthetic strategies including novel reagents like bromodimethylborane and low temperatures, we were able to prevent acyl migration. Several homologous series of glycerol derivatives were synthesized and the influence of molecular packing on physical properties was studied. This fundamental understanding was then utilized to chemically modify the structure of natural oils to impart the functional properties required for new applications such as lubricants, paints and plasticizers. A number of chemical transformations such as trans-esterification, cyclopropanation, cyclization, epoxidation, and branching were used to generate structural heterogeneity, reduced molecular weight, disrupted packing, and a change of polarity that resulted in the required functionality and performance for a chosen application, thus creating new value-added products.