Cycloaddition Chemistry for the Synthesis of Heterocyclic Compounds and Progress Towards the Total Synthesis of Grandilodine A
Doctor of Philosophy
Brian L. Pagnekopf
This thesis describes three separate research projects within the broad topic of synthetic organic chemistry. The synthesis of alkyl-substituted siloles and their reactivity in Diels-Alder chemistry is reported. Furthermore, the cleavage of the bicyclic adducts by Tamao-Fleming oxidation has been achieved which reveals a highly substituted cyclohexene-1,4-diol structure.
The second chapter describes the cycloaddition chemistry of alkoxy-activated cyclobutane dicarboxylates with aldehydes, nitrones and nitrosoarenes. The cycloaddition occurs, in the case of aldehydes, with uniformly high diastereoselectivity to afford tetrahydropyrans in good to excellent yield. When nitrones were used as the dipolarophile the cycloaddition occurs in a rather unselective manner though the formed oxazepanes undergo equilibration to yield single diastereomers in most cases. The cycloaddition with nitrosoarenes, however, proved an exception as the regioselectivity of the reaction was dependant both on the nitrosoarenes and the catalyst employed.
Lastly, progress towards the synthesis of grandilodine A is reported. Several routes were developed in attempts to form the central 8-membered ring; however successful ring closure has eluded this study.
Stevens, Andrew C., "Cycloaddition Chemistry for the Synthesis of Heterocyclic Compounds and Progress Towards the Total Synthesis of Grandilodine A" (2013). Electronic Thesis and Dissertation Repository. 1364.