A concise and efficient total synthesis of roseophilin has been proposed. Roseophilin is a unique and very unusual ansa-bridged azafulvene natural product which has been isolated from the culture broths of Streptomyces griseoviridis. The natural product shows activity against several human tumor cell lines in submicromolar concentration and is therefore an attractive lead compound for pharmaceutical development, the more so since this compound may represent an unusual mechanism of action. The chemical synthesis which is being proposed makes use of a method for creating the central ring structure which is ideally suited to this target. Application of this non-obvious strategy makes it possible to assemble the entire core structure in ten linear steps. In this way, total synthesis become an efficient means for preparing both the natural material and also for preparing functional analogs of the natural product. The enantioselective version of the key cyclization reaction will be developed in a general context and then applied to the roseophilin synthesis. Since the absolute stereochemistry of the natural product has not been determined, the question will be answered through total synthesis. The key structure which is embedded within the roseophilin tricyclic core, the cross-conjugated cyclopentenone, is also present in a number of other pharmacologically active natural products, therefore the proposed research is broad in scope. One of the long-term goals of this work is to apply the enantioselective version of the key cyclization reaction to the syntheses of these structures.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM057873-02
Application #
6019445
Study Section
Medicinal Chemistry Study Section (MCHA)
Project Start
1998-08-01
Project End
2001-07-31
Budget Start
1999-08-01
Budget End
2000-07-31
Support Year
2
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Hawaii
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
121911077
City
Honolulu
State
HI
Country
United States
Zip Code
96822
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Bow, William F; Basak, Ashok K; Jolit, Anais et al. (2010) Enamine-iminium ion Nazarov cyclization of alpha-ketoenones. Org Lett 12:440-3
Dixon, Darryl D; Tius, Marcus A; Pratt, Lawrence M (2009) Gas phase and solution structures of 1-methoxyallenyllithium. J Org Chem 74:5881-6
Basak, Ashok K; Tius, Marcus A (2008) Interrupting the Nazarov cyclization with indoles. Org Lett 10:4073-6
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Banaag, April R; Tius, Marcus A (2007) Design of chiral auxiliaries for the allene ether nazarov cyclization. J Am Chem Soc 129:5328-9

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