ORGN 672 |
| Machaeriols A, B, C, and D bearing the cannabinoid structure,were recently isolated from the bark of the Machaerium multiflorum spruce. They have been reported to have potential in vitro antimicrobial activity against Staphylococcus aureus and methicillin-resistant S. aureus. They also showed potent in vitro antimalarial activity against Plasmodium falciparum D6 and W2 clones. These important biological activities have led to the development of a variety of synthetic approaches to these natural products. Total synthesis of biologically interesting (+)-machaeriols A, C, and their enantiomers has been achieved from a readily available aryl aldehyde or aryl ester, respectively. The key steps are stilbene formation by a Horner-Wadsworth-Emmons reaction and trans-hexahydrodibenzopyran formation by domino reaction. The concise synthesis of (+)-machaeriol B and its enantiomer has been also accomplished from o-phenylhydroxyamine in 4 steps. The key strategies in the syntheses of (+)-machaeriol B and its enantiomer involved benzofuran formation through a [3,3]-sigmatropic rearrangement and trans-hexahydrodibenzopyran formation by a domino reaction. |
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Heterocycles and Aromatics, Asymmetric Reactions and Syntheses and Total Synthesis of Complex Molecules
7:00 PM-9:00 PM, Wednesday, August 19, 2009 Walter E. Washington Convention Center -- Ballroom C, Poster
Division of Organic Chemistry |