Date of Award
Doctor of Philosophy (PhD)
Professor D. B. MacLean
A new reaction between phthalide ortho esters with a series of dienophiles has been studied. It was found that treatment of 1,1-diethoxyphthalan or 5,6-dimethoxy-1,1-diethoxyphthalan with activated acetylenes yielded tetrasubstituted naphthalenes. Reaction of 1,1-diethoxyphthalan with diethyl maleate afforded a mixture of enol ethers and a trisubstituted naphthalene. The enol ethers were converted into a disubstituted naphthol under acidic conditions. Treatment of phthalide ortho esters with 1,4-benzoquinone or 1,4-napththoquinone gave p-homoquinones instead of the expected linear tricyclic and tetracyclic aromatic compounds.
The formation of the compounds derived from the reaction of phthalide ortho esters with dienophiles has been rationalized in terms of a mechanism that involves l-ethoxyisobenzofurans as intermediates.
Contreras, Luis, "Reactions of Phthalide Ortho Esters with Dienophiles: Synthesis of Naphthalenes and Homoquinones" (1980). Open Access Dissertations and Theses. Paper 633.