The application's broad, long-term objectives are the development of highly enantio- and diastereoselective chiral reagents/methods for the efficient synthesis of a variety of 100% enantiomerically pure substances, which are in great demand in natural product synthesis, biomedical and pharmaceutical research.
The specific aims of the proposal include: (1) Asymmetric cyclic hydroboration to achieve a highly stereoselective synthesis of optically pure trans-[n,n']-fused rings (n = 5,6,7,8...; n' = 5,6,7,8). (2) Development of newer and more powerful chiral auxiliaries for achieving 100% stereo-selective asymmetric hydroboration. (3) Development of practical methods for the synthesis of a variety of 100% enantiomerically pure organic compounds from readily available optically pure boron intermediates. (4) Development of convenient methods to recycle the chiral auxiliary after allyl- and crotylboration in order to make our reagents highly cost- effective, even for industrial applications. (5) Investigation of asymmetric crotylborations of various aldehydes at - 100 oC to achieve the highest possible enantio- and diastereoselectivities, which can directly benefit polyether antibiotic synthesis. (6) Exploration of the asymmetric allyl- and crotylborations of representative heterocyclic aldehydes to develop powerful new methods for the asymmetric synthesis of a multitude of heterocyclic natural products. (7) Exploration of new strategies/new reagents for the asymmetric synthesis of (a) 4-substituted-gamma-lactones, to provide valuable routes to optically active pheromones and other natural products; (b) substituted spiroketals, to offer enantioselective routes to macrolide antibiotics; (c) 6-substituted-5,6-dihydro-2-pyranones, to develop stereoselective routes to many biologically important natural products (see background and significance); (d) substituted tetrahydrofurans and tetrahydropyrans, to provide completely stereoselective routes to various monocarboxylic acid ionophores. (8) Application of powerful new allyl- and crotylborane reagents and favorable experimental conditions to solve the mismatch problems encountered in double asymmetric synthesis.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM010937-29A1
Application #
3268192
Study Section
Medicinal Chemistry Study Section (MCHA)
Project Start
1976-05-01
Project End
1994-11-30
Budget Start
1991-12-15
Budget End
1992-11-30
Support Year
29
Fiscal Year
1992
Total Cost
Indirect Cost
Name
Purdue University
Department
Type
Schools of Arts and Sciences
DUNS #
072051394
City
West Lafayette
State
IN
Country
United States
Zip Code
47907
Joshi, N N; Srebnik, M (1989) Resolution of rac-1,2-halohydrins by chiral complexation gas chromatography. J Chromatogr 462:458-60