Please use this identifier to cite or link to this item:
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
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
DOI: 10.3390/molecules27154904
Publisher Version:
Appears in Collections:CICECO - Artigos
DQ - Artigos
REQUIMTE - Artigos

Files in This Item:
File Description SizeFormat 
molecules-27-04904.pdf2.36 MBAdobe PDFView/Open

Formato BibTex MendeleyEndnote Degois 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.