Synthesis and NMR assignment of pentacycloundecane precursors of potential pharmaceutical agents |
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| Authors: | Oluseye K. Onajole Maya M. Makatini Patrick Govender Thavendran Govender Glenn E. M. Maguire Hendrik G. Kruger |
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| Affiliation: | 1. School of Chemistry, University of KwaZulu‐Natal, Durban, South Africa;2. School of Biochemistry, Genetics and Microbiology, University of KwaZulu‐Natal, Durban, South Africa;3. School of Pharmacy and Pharmacology, University of KwaZulu‐Natal, Durban, South Africa |
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| Abstract: | The synthesis and complete NMR elucidation of eight novel pentacycloundecane (PCU) derivatives are reported. These compounds are precursors in the synthesis of PCU‐based anti‐tuberculosis (TB) agents and potential human immunodeficiency virus (HIV) protease inhibitors. Two‐dimensional (2D) NMR techniques were used to assign the NMR spectra for these compounds. Substitution of the cage molecule at (C‐8/11) further complicates the assignment, since some of the substituted alkyl chain groups overlap with the cage proton signals. The side chain heteroatoms also introduce a rare through‐space deshielding effect to some of the carbon atoms of the cage skeleton. Ring strain in the rigid cage skeleton appears to induce drastic electronic changes in some parts of the cage framework. This observation is more dramatic for the C‐4 methylene group of the cage diols and the cage ethers. Copyright © 2010 John Wiley & Sons, Ltd. |
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| Keywords: | NMR pentacycloundecane through‐space deshielding PCU |
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