Although many synthetic and biological transformations involve oxocarbenium ion intermediates, details about the structure and reactivity of these highly reactive species remain unknown. For example, debate continues about the preferred conformation of the mannosyl cation, although drugs targeting this cation have been tested to treat genetic and viral diseases as well as cancer. In other cases, inconsistencies in the literature remain, such as the nature of anchimeric assistance in stereoselective glycosylation. This proposal builds upon our work during the last funding period that demonstrates the influence of heteroatom substituents on the conformations of oxocarbenium ions and thus the stereoselectivity of their reactions. We have devised an approach to solving the structure of the mannosyl cation, and we will gain insight into the nature of anchimeric assistance. We have also devised new stereoselective synthetic methods based upon oxocarbenium and peroxocarbenium ion intermediates. ? ? This proposal will have considerable implications for public health. For example, our studies on the three- dimensional structures of carbohydrate-derived intermediates will impact the design of drugs for the treatment of diabetes, hepatitis, HIV, and cancer. In addition, our studies on the structure and reactivity of these intermediates will enable chemists to prepare those drugs more efficiently. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM061066-07
Application #
7433920
Study Section
Synthetic and Biological Chemistry A Study Section (SBCA)
Program Officer
Schwab, John M
Project Start
2000-04-01
Project End
2010-05-31
Budget Start
2008-06-01
Budget End
2009-05-31
Support Year
7
Fiscal Year
2008
Total Cost
$236,481
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
Beaver, Matthew G; Buscagan, Trixia M; Lavinda, Olga et al. (2016) Stereoelectronic Model To Explain Highly Stereoselective Reactions of Seven-Membered-Ring Oxocarbenium-Ion Intermediates. Angew Chem Int Ed Engl 55:1816-9
Garcia, Angie; Sanzone, Jillian R; Woerpel, K A (2015) Participation of alkoxy groups in reactions of acetals: violation of the reactivity/selectivity principle in a Curtin-Hammett kinetic scenario. Angew Chem Int Ed Engl 54:12087-90
Otte, Douglas A L; Woerpel, K A (2015) Evidence that Additions of Grignard Reagents to Aliphatic Aldehydes Do Not Involve Single-Electron-Transfer Processes. Org Lett 17:3906-9
Garcia, Angie; Otte, Douglas A L; Salamant, Walter A et al. (2015) Acceleration of acetal hydrolysis by remote alkoxy groups: evidence for electrostatic effects on the formation of oxocarbenium ions. Angew Chem Int Ed Engl 54:3061-4
Garcia, Angie; Otte, Douglas A L; Salamant, Walter A et al. (2015) Influence of alkoxy groups on rates of acetal hydrolysis and tosylate solvolysis: electrostatic stabilization of developing oxocarbenium ion intermediates and neighboring-group participation to form oxonium ions. J Org Chem 80:4470-80
Kendale, Joanna C; Valentín, Elizabeth M; Woerpel, K A (2014) Solvent effects in the nucleophilic substitutions of tetrahydropyran acetals promoted by trimethylsilyl trifluoromethanesulfonate: trichloroethylene as solvent for stereoselective C- and O-glycosylations. Org Lett 16:3684-7
Lavinda, Olga; Tran, Vi Tuong; Woerpel, K A (2014) Effect of conformational rigidity on the stereoselectivity of nucleophilic additions to five-membered ring bicyclic oxocarbenium ion intermediates. Org Biomol Chem 12:7083-91
Otte, Douglas A L; Borchmann, Dorothee E; Lin, Chin et al. (2014) 13C NMR spectroscopy for the quantitative determination of compound ratios and polymer end groups. Org Lett 16:1566-9
Tran, Vi Tuong; Woerpel, K A (2013) Nucleophilic addition to silyl-protected five-membered ring oxocarbenium ions governed by stereoelectronic effects. J Org Chem 78:6609-21
Dibble, David J; Ziller, Joseph W; Woerpel, K A (2011) Spectroscopic and X-ray crystallographic evidence for electrostatic effects in 4-substituted cyclohexanone-derived hydrazones, imines, and corresponding salts. J Org Chem 76:7706-19

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