Discipline: Chemistry and Chemical Sciences
Subcategory: Chemistry (not Biochemistry)
Room: Exhibit Hall
Zahria Patrick - University of Missouri - St.Louis
Co-Author(s): Madison Clark, University of Missouri - Columbia, Columbia, MO
The aim of this research project is to expand the scope of the 4 + 3 cycloadduct chemistry by varying the functional group attached to the prerequisite oxidopyridinium ion for each respective cycloadduct product. These products can be used to help make derivatives of a class of molecules called Daphnicyclidin A which can be effective against illnesses such as murine lymphoma. While N-substitution of the pyridinium precursor is known to proceed smoothly if alkylated by a lone methyl group, we evaluated the affect a larger, more robust alkyl group would have on the overall yield of the 4 + 3 cycloadduct product. Isobutyl triflate, generated from the known reaction between isobutyl alcohol and triflic anhydride, was reacted with ethyl 5-hydroxy-nicotinate to generate the respective N-isobutyl oxidopyridinium ion in quantitative yield, which subsequently underwent a 4 + 3 cycloaddition reaction with 2,3-diemethylbutadiene to generate the desired 4 + 3 cycloadduct in 67% yield. Furthermore, we experimented with N-acyl substitution of the oxidopyridinium ion in 4 + 3 cycloaddition reactions. (Trans)-2-phenylcyclohexyl 2-chloroacetate, derived from (trans)-2-phenylcyclohexanol, and chloroacetyl chloride using a known literature procedure, were reacted with ethyl 5-hydroxy-nicotinate to generate the respective N-acyl oxidopyridinium ion in quantitative yield, which subsequently underwent a 4 + 3 cycloaddition reaction with 2,3-diemethylbutadiene to generate the desired 4 + 3 cycloadduct in 28% yield. While we were able to cleanly obtain the desired 4 + 3 cycloadduct products for each derivative, reaction condition modifications are necessary to improve the overall yields for each of the new compounds. Future research could include modifying the conditions of the aforementioned reactions to achieve better results and running these reactions with different substituents to obtain new derivatives of the (4+3) cycloadduct product.
Funder Acknowledgement(s): National Science Foundation, Stevens Fellows Undergraduate Research Program
Faculty Advisor: Michael Harmata, firstname.lastname@example.org
Role: All aspects of this research were done by me under the guidance and supervision of my faculty mentor and the graduate and undergraduate students in the research lab.