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The lyconadins: enantioselective total syntheses of (+)-lyconadin A and (-)-lyconadin B.

ABSTRACT: A full account of the enantioselective total syntheses of (+)-lyconadin A (1) and (-)-lyconadin B (2) is presented. Central to this venture was recognition and deployment of a key strategy-level intramolecular aldol/conjugate addition cascade that led, in a single operation, to two new carbon-carbon sigma-bonds, three new stereogenic centers, and two new rings, albeit with the incorrect stereogenicity at C(12) for the lyconadins. Correction of the C(12) stereogenicity was achieved via innovative use of a protonated intramolecular aminal. An aminoiodo olefin cyclization, in conjunction with alpha-pyridinone and 3,4-dihydropyridinone annulation protocols, permitted completion of the syntheses of (+)-lyconadin A (1) and (-)-lyconadin B (2), respectively.

SUBMITTER: Beshore DC

PROVIDER: S-EPMC2819465 | biostudies-literature | 2008 Oct

REPOSITORIES: biostudies-literature

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The lyconadins: enantioselective total syntheses of (+)-lyconadin A and (-)-lyconadin B.

Beshore Douglas C DC Smith Amos B AB

Journal of the American Chemical Society 20080918 41

A full account of the enantioselective total syntheses of (+)-lyconadin A (1) and (-)-lyconadin B (2) is presented. Central to this venture was recognition and deployment of a key strategy-level intramolecular aldol/conjugate addition cascade that led, in a single operation, to two new carbon-carbon sigma-bonds, three new stereogenic centers, and two new rings, albeit with the incorrect stereogenicity at C(12) for the lyconadins. Correction of the C(12) stereogenicity was achieved via innovative ...[more]

PMID: 18798629

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