Date of Award

Summer 2000

Degree Type

Thesis - Restricted

Degree Name

Master of Science (MS)




It was proposed by our research group that thermal rearrangement of spiroactivated phenyl substituted dicarbonyl cyclopropanes gave dihydrofurans through a zwitterion intermediate. It is also our interest to know the effect of replacing the phenyl group with a vinyl group. The thermal rearrangement products can be identified by NMR spectroscopy. Mechanistic studies were carried out to answer the question of whether the reaction is concerted, or proceeds through a zwitterion pathway. The solvent effect, activation parameter, and stereochemical data obtained in this study strongly suggest a concerted pathway for the [3,3] sigmatropic rearrangement which leads to a 2,5-dihydrooxepin and a zwitterion intermediate for the [1 ,3] sigmatropic rearrangement that results in the formation of a dihydrofuran.