This grant in Organic and Macromolecular Chemistry provides support for the research of Professor Joseph Gajewski of Indiana University. This work is focused on using secondary kinetic isotope effects and stereochemistry to determine transition state structures in concerted reactions. Strategies have also been developed to demonstrate the possible existence of intermediates in certain allylic rearrangements. The reactions to be studied include 1,3-shifts in the vinylcyclopropane rearrangement; 3,3-sigmatropic shifts of substrates with strong electron withdrawing groups at C-2; ionic 3,3-shifts; 2+2, 2+3, and 2+4 cycloadditions; and carbonyl additions. Attempts will also be made to parameterize transition state bond lengths, angles, and constants for molecular mechanics calculations of diastereoselectivity in pericyclic reactions and carbonyl additions. Work of the type supported in this grant is essential if we are to understand the dynamics of simple organic reactions. Such understanding provides the necessary foundation for studies of chemical reactivity in complex molecular systems.
