9018164 This grant from the Organic Dynamics Program supports the continuing work of Professor Gajewski at Indiana University. The results of this research will provide fundamental information about the exact mode by which organic molecules undergo thermal reactions and rearrangements. One of the questions to be answered is, are there short-lived intermediates in these processes or do they occur in a one step process without intermediates? Knowledge of these processes is important to a basic understanding of organic chemistry. Dr. Gajewski's research will provide basic information about thermal reactions and rearrangements in several areas. There is a concern that the preferred suprafacial-inversion stereochemistry in methylvinyl cyclopropanes is determined by substituent effects rather than by orbital symmetry. An attempt will be made to resolve this question by the use of deuterium isotope effects. Another phase of the research deals with oxyanionic vinyl cyclopropane and cyclobutane rearrangements, where two orbital symmetry allowed concerted reactions and a stepwise reaction are possible. Deuterium isotope effects will be used to sort out these possible mechanisms as a function of solvent and counterion. In addition, substituent effects on Cope rearrangements will be studied and the question of double rotation in the thermolysis of spiropentane geometric isomerization will be pursued.
