ORGN 504 |
| Acyl halide-aldehyde cyclocondensation (AAC) reactions achieve the [2+2] cycloaddition of in situ generated ketene and aldehyde electrophiles to afford mono- or cis-disubstituted ß-lactones. The mechanistic details pertaining to the development of asymmetric cinchona alkaloid-catalyzed AAC reactions of both simple ketene and substituted ketenes will be described. The utility of the alkaloid-catalyzed AAC reactions as surrogates for catalytic asymmetric ester enolate aldol additions will be discussed. Iterative application of the enantioselective AAC reactions provides a catalytic asymmetric synthesis of polypropionate architecture. Applications of this reaction technology to investigations directed toward the total synthesis of amphidinolide B and pironetin A will also be presented.
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New Reactions and Methodology
8:00 AM-12:00 PM, Wednesday, 31 August 2005 Washington DC Convention Center -- Ballroom B, Oral
Division of Organic Chemistry |
