ORGN 367 |
| David P. Brown and Lalitha Krishnamurthy. Chemistry, St. John's University, 8000 Utopia Parkway, Jamaica, NY 11439 |
| The synthesis of seven and larger membered heterocyclic ring compounds from linear sybstrates, albeit a difficult process, has been well established, with the methodology of electrophilic heteroatom cyclization being among the widely used approach. Generally, for eight and larger membered compounds, these cyclizations are of greater practical merit when steric constraints are introduced into the chain. Medium and large ring lactones were routinely prepared from unsaturated carboxylic acids, employing a variety of electrophilic reagents, wherein products of exo- and endo-cyclizations were observed. Among the structural modifications that would promote cyclization is the oxygen effect that results when an oxygen atom in introduced in the carbon chain. We report the three-step conversion of dihydrocoumarin systems into some novel nine- and ten-membered lactones in modest yields. |
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Physical Organic, Materials, Heterocycles, Aromatics, Metal-Mediated Reactions
8:00 PM-10:00 PM, Tuesday, September 9, 2003 Hilton New York -- Americas Hall 1, Poster
Division of Organic Chemistry |