The goals of this proposal are to develop new reactions based on the Prins cyclization and to apply these new reactions to the synthesis of complex natural products. New methods to be developed include the second generation Mukaiyama aldol Prins (MAP) reaction with unactivated alkenes. A new cascade cyclization reaction between enones and enol ethers has been discovered that will be investigated. The mechanism of the Prins cyclization will be studied, and the role of 2-oxonia Cope rearrangements will be investigated. The surprising axial selective in Prins cyclizations promoted by TMSBr cyclization will be studied both mechanistically and as a practical preparative procedure. Syntheses based on this new methodology include routes to calyxin I, a second-generation synthesis of leucascandrolide A, lasonolide A and kendomycin. Both leucascandrolide A and lasonolide A have shown potent cytotoxicity against human cancer cell lines, and the planned syntheses are more concise and efficient than any yet reported for these important compounds. The work described herein will advance the state of synthetic chemistry and provide new tools for organic chemists. These tools will facilitate the synthesis of many new structures that may be important as new pharmaceutical agents.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
2R01CA081635-07A1
Application #
6865345
Study Section
Special Emphasis Panel (ZRG1-BPC-B (02))
Program Officer
Lees, Robert G
Project Start
1998-09-04
Project End
2008-08-30
Budget Start
2004-09-23
Budget End
2005-08-31
Support Year
7
Fiscal Year
2004
Total Cost
$247,732
Indirect Cost
Name
University of California Irvine
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
046705849
City
Irvine
State
CA
Country
United States
Zip Code
92697
Bahnck, Kevin B; Rychnovsky, Scott D (2008) Formal synthesis of (-)-kendomycin featuring a Prins-cyclization to construct the macrocycle. J Am Chem Soc 130:13177-81
Tadpetch, Kwanruthai; Rychnovsky, Scott D (2008) Rhenium(VII) catalysis of Prins cyclization reactions. Org Lett 10:4839-42
Gesinski, Michael R; Van Orden, Lori J; Rychnovsky, Scott D (2008) Lewis Acid-Promoted Mukaiyama Aldol-Prins (MAP) Cyclizations of Acetals, Ketals, yy-Acetoxy Ethers, and Orthoformates. Synlett 2008:363-366
Tian, Xia; Rychnovsky, Scott D (2007) Synthesis and structural reassignment of (+)-epicalyxin F. Org Lett 9:4955-8
Van Orden, Lori J; Patterson, Brian D; Rychnovsky, Scott D (2007) Total synthesis of leucascandrolide a: a new application of the Mukaiyama aldol-Prins reaction. J Org Chem 72:5784-93
Jasti, Ramesh; Rychnovsky, Scott D (2006) Racemization in Prins cyclization reactions. J Am Chem Soc 128:13640-8
Bahnck, Kevin B; Rychnovsky, Scott D (2006) Rapid stereocontrolled assembly of the fully substituted C-aryl glycoside of kendomycin with a Prins cyclization: a formal synthesis. Chem Commun (Camb) :2388-90
Tian, Xia; Jaber, James J; Rychnovsky, Scott D (2006) Synthesis and structure revision of calyxin natural products. J Org Chem 71:3176-83
Jasti, Ramesh; Rychnovsky, Scott D (2006) Solvolysis of a tetrahydropyranyl mesylate: mechanistic implications for the Prins cyclization, 2-oxonia-cope rearrangement, and Grob fragmentation. Org Lett 8:2175-8
Bolla, Megan L; Patterson, Brian; Rychnovsky, Scott D (2005) Tetrahydropyran rings from a Mukaiyama-Michael cascade reaction. J Am Chem Soc 127:16044-5

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