Synthesis of 2-hydroxy-3-(2-methyl-propenyl)-1,4-naphthoquinone and related oxime derivatives
<div class="WordSection1"><p><em>The condensation reaction</em><em> of commercial 2-hydroxy-1 ,4-naphthoquinone <strong>1 </strong>(lawsone) with isobutyraldehyde <strong>2</strong> furnishs norlapachol <strong>3 </strong>(2...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Universidade Federal de Mato Grosso do Sul
2012-06-01
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| Series: | Orbital: The Electronic Journal of Chemistry |
| Subjects: | |
| Online Access: | http://orbital.ufms.br/index.php/Chemistry/article/view/368 |
| _version_ | 1818976840428027904 |
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| author | Patricia S. Oliveira Celso A Camara |
| author_facet | Patricia S. Oliveira Celso A Camara |
| author_sort | Patricia S. Oliveira |
| collection | DOAJ |
| description | <div class="WordSection1"><p><em>The condensation reaction</em><em> of commercial 2-hydroxy-1 ,4-naphthoquinone <strong>1 </strong>(lawsone) with isobutyraldehyde <strong>2</strong> furnishs norlapachol <strong>3 </strong>(2-hydroxy-3-(2-methyl-propenyl) -1,4-naphthoquinone) with yields ranging from 66 to 93% depending on the different conditions tested, and a reaction temperature factor determinant for the formation of the desired product. It was treated with hydroxylamine hydrochloride in alkaline (NaOH) to provide the oxime <strong>4</strong> from regioselective modification of the carbonyl C-1 with 91% yield.</em><strong> </strong><em>The</em><em> regioselectivity of the reaction can be explained by analyzing the </em><em></em><em></em><em>different</em><em> resonance structures which can be seen that the carbonyl C-4 is less electrophilic than C-1. In this work was also obtained the oxime <strong>5</strong>, <strong>6</strong> and <strong>7</strong> from lapachol, αlpha and β-lapachone, respectively, in yields of 64-85%. The oximes of αlpha and β-norlapachone, <strong>8</strong> and <strong>9</strong> are in obtention. </em><em>All the products were analyzed by IR and NMR, and were observed that oximes of lapachol and norlapachol are isolated as E/Z mixtures. Two-dimensional NOE-type experiments of the corresponding acylated derivative will be made to help identify the proportion of the mixture.</em></p></div> |
| first_indexed | 2024-12-20T16:18:14Z |
| format | Article |
| id | doaj.art-4fd8cd1a56a646298ab2a43bef4c3d6d |
| institution | Directory Open Access Journal |
| issn | 1984-6428 |
| language | English |
| last_indexed | 2024-12-20T16:18:14Z |
| publishDate | 2012-06-01 |
| publisher | Universidade Federal de Mato Grosso do Sul |
| record_format | Article |
| series | Orbital: The Electronic Journal of Chemistry |
| spelling | doaj.art-4fd8cd1a56a646298ab2a43bef4c3d6d2022-12-21T19:33:43ZengUniversidade Federal de Mato Grosso do SulOrbital: The Electronic Journal of Chemistry1984-64282012-06-0141616210.17807/orbital.v4i1.368138Synthesis of 2-hydroxy-3-(2-methyl-propenyl)-1,4-naphthoquinone and related oxime derivativesPatricia S. Oliveira0Celso A Camara1Departamento de Ciências Moleculares, Universidade Federal Rural de PernambucoDepartamento de Ciências Moleculares, Universidade Federal Rural de Pernambuco<div class="WordSection1"><p><em>The condensation reaction</em><em> of commercial 2-hydroxy-1 ,4-naphthoquinone <strong>1 </strong>(lawsone) with isobutyraldehyde <strong>2</strong> furnishs norlapachol <strong>3 </strong>(2-hydroxy-3-(2-methyl-propenyl) -1,4-naphthoquinone) with yields ranging from 66 to 93% depending on the different conditions tested, and a reaction temperature factor determinant for the formation of the desired product. It was treated with hydroxylamine hydrochloride in alkaline (NaOH) to provide the oxime <strong>4</strong> from regioselective modification of the carbonyl C-1 with 91% yield.</em><strong> </strong><em>The</em><em> regioselectivity of the reaction can be explained by analyzing the </em><em></em><em></em><em>different</em><em> resonance structures which can be seen that the carbonyl C-4 is less electrophilic than C-1. In this work was also obtained the oxime <strong>5</strong>, <strong>6</strong> and <strong>7</strong> from lapachol, αlpha and β-lapachone, respectively, in yields of 64-85%. The oximes of αlpha and β-norlapachone, <strong>8</strong> and <strong>9</strong> are in obtention. </em><em>All the products were analyzed by IR and NMR, and were observed that oximes of lapachol and norlapachol are isolated as E/Z mixtures. Two-dimensional NOE-type experiments of the corresponding acylated derivative will be made to help identify the proportion of the mixture.</em></p></div>http://orbital.ufms.br/index.php/Chemistry/article/view/368norlapachollapachollapachonesoxime |
| spellingShingle | Patricia S. Oliveira Celso A Camara Synthesis of 2-hydroxy-3-(2-methyl-propenyl)-1,4-naphthoquinone and related oxime derivatives Orbital: The Electronic Journal of Chemistry norlapachol lapachol lapachones oxime |
| title | Synthesis of 2-hydroxy-3-(2-methyl-propenyl)-1,4-naphthoquinone and related oxime derivatives |
| title_full | Synthesis of 2-hydroxy-3-(2-methyl-propenyl)-1,4-naphthoquinone and related oxime derivatives |
| title_fullStr | Synthesis of 2-hydroxy-3-(2-methyl-propenyl)-1,4-naphthoquinone and related oxime derivatives |
| title_full_unstemmed | Synthesis of 2-hydroxy-3-(2-methyl-propenyl)-1,4-naphthoquinone and related oxime derivatives |
| title_short | Synthesis of 2-hydroxy-3-(2-methyl-propenyl)-1,4-naphthoquinone and related oxime derivatives |
| title_sort | synthesis of 2 hydroxy 3 2 methyl propenyl 1 4 naphthoquinone and related oxime derivatives |
| topic | norlapachol lapachol lapachones oxime |
| url | http://orbital.ufms.br/index.php/Chemistry/article/view/368 |
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