Some Diels-Alder reactions of benzyne.

  • Sandra Elaine Ward

Student thesis: Doctoral ThesisPhD


The original intention of this project was to extend and examine more closely the synthesis of phenanthrenes by the addition of benzyne to styrenes and arylacetylenes which had already been reported by this labarotary. Accordingly, Chapter 1 is a fairly extensive review of existing routes to the phenanthrene ring system, compiled in the absence of a comprehensive published survey, while Chapter 2 briefly summarises the chemistry of benzyne, In Chapter 3, general experimental techniques (spectroscopic and chromatographic methods) are described. Chapter 4 describes the reactions of isosafrole with benzyne generated by a variety of methods in an attempt to maximise yields of phenanthrenes. With benzenediazonium-2-carboxylate hydrochloride, however, the main product was trans-3-(3',4'-methylenedioxyphenyl)-4-methyl-3,4-dihydroisocoumarin. It therefore seemed that reaction of this benzyne precursor with styrenes might be a good preparative method for 3-aryl-3,4-dihydroisocoumarins and Chapter 5 compares the reactions of benzenediazonium-2-carboxylate hydrochloride with anethole, styrene, and isoeugenol methyl ether. Attempts to extend this reaction to the synthesis of 3-arylisocoumarins by reacting arylacetylenes e.g. phenylacetylene and 3,4-dimethoxyphenylacetylene, with benzenediazonium-2-carboxylate hydrochloride are described in Chapter 6.
Date of Award1971
Original languageEnglish
Awarding Institution
  • University of Bath

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