Please use this identifier to cite or link to this item:
http://hdl.handle.net/10773/36109
Title: | Decoration of A-ring of a lupane-type triterpenoid with different oxygen and nitrogen heterocycles |
Author: | Sousa, Joana L. C. Albuquerque, Hélio M. T. Silvestre, Armando J. D. Silva, Artur M. S. |
Keywords: | Triterpenoids Betulinic acid Oxygen heterocycles Nitrogen heterocycles Diastereoselectivity Michael addition |
Issue Date: | Aug-2022 |
Publisher: | MDPI |
Abstract: | Betulinic acid (BA) was used as starting building block to create a library of novel BA-derived compounds containing O- and N-heterocycles. Firstly, BA was converted into methyl betulonate (BoOMe), which was used as intermediate in the developed methodologies. 1,2-Oxazine-fused BoOMe compounds were obtained in 12–25% global yields through a Michael addition of nitromethane to methyl (E)-2-benzylidenebetulonate derivatives, followed by nitro group reduction and intramolecular cyclization. Remarkably, the triterpene acts as a diastereoselective inducer in the conjugate addition of nitromethane, originating only one diastereomer out of four possible ones. Furthermore, other oxygen and nitrogen-containing heterocycles were installed at the A-ring of BoOMe, affording 2-amino-3-cyano-4H-pyran-fused BoOMe, diarylpyridine-fused BoOMe and 1,2,3-triazole–BoOMe compounds, using simple and straightforward synthetic methodologies. Finally, BA was revealed to be a versatile starting material, allowing the creation of a molecular diversification of compounds containing a triterpenic scaffold and O- and N-heterocycles. |
Peer review: | yes |
URI: | http://hdl.handle.net/10773/36109 |
DOI: | 10.3390/molecules27154904 |
Publisher Version: | https://www.mdpi.com/1420-3049/27/15/4904 |
Appears in Collections: | CICECO - Artigos DQ - Artigos REQUIMTE - Artigos |
Files in This Item:
File | Description | Size | Format | |
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molecules-27-04904.pdf | 2.36 MB | Adobe PDF | View/Open |
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