Synthesis of 2-Deoxybrassinosteroids Analogs with 24-nor, 22(S)-23-Dihydroxy-Type Side Chains from Hyodeoxycholic Acid
Natural brassinosteroids are widespread in the plant kingdom and it is known that they play an important role in regulating plant growth. In this study, two new brassinosteroid analogs with shorter side chains but keeping the diol function were synthesized. Thus, the synthesis of 2-deoxybrassinoster...
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MDPI AG
2018-05-01
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| Series: | Molecules |
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| Online Access: | http://www.mdpi.com/1420-3049/23/6/1306 |
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| author | Rodrigo Carvajal Cesar González Andrés F. Olea Mauricio Fuentealba Luis Espinoza |
| author_facet | Rodrigo Carvajal Cesar González Andrés F. Olea Mauricio Fuentealba Luis Espinoza |
| author_sort | Rodrigo Carvajal |
| collection | DOAJ |
| description | Natural brassinosteroids are widespread in the plant kingdom and it is known that they play an important role in regulating plant growth. In this study, two new brassinosteroid analogs with shorter side chains but keeping the diol function were synthesized. Thus, the synthesis of 2-deoxybrassinosteroids analogs of the 3α-hydroxy-24-nor, 22,23-dihydroxy-5α-cholestane side chain type is described. The starting material is a derivative from hyodeoxycholic acid (4), which was obtained with an overall yield of 59% following a previously reported five step route. The side chain of this intermediate was modified by oxidative decarboxylation to get a terminal olefin at the C22-C23 position (compound 20) and subsequent dihydroxylation of the olefin. The resulting epimeric mixture of 21a, 21b was separated and the absolute configuration at the C22 carbon for the main product 21a was elucidated by single crystal X-ray diffraction analysis of the benzoylated derivative 22. Finally, lactonization of 21a through a Baeyer-Villiger oxidation of triacetylated derivative 23, using CF3CO3H/CHCl3 as oxidant system, leads to lactones 24 and 25 in 35% and 14% yields, respectively. Deacetylation of these compounds leads to 2-deoxybrassinosteroids 18 and 19 in 86% and 81% yields. Full structural characterization of all synthesized compounds was achieved using their 1D, 2D NMR, and HRMS data. |
| first_indexed | 2024-12-12T12:55:26Z |
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| id | doaj.art-9106d7b56b1d410a931663db5f2b9440 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-12-12T12:55:26Z |
| publishDate | 2018-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-9106d7b56b1d410a931663db5f2b94402022-12-22T00:23:53ZengMDPI AGMolecules1420-30492018-05-01236130610.3390/molecules23061306molecules23061306Synthesis of 2-Deoxybrassinosteroids Analogs with 24-nor, 22(S)-23-Dihydroxy-Type Side Chains from Hyodeoxycholic AcidRodrigo Carvajal0Cesar González1Andrés F. Olea2Mauricio Fuentealba3Luis Espinoza4Departamento de Química, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2340000, ChileDepartamento de Química, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2340000, ChileInstituto de Ciencias Químicas Aplicadas, Facultad de Ingeniería, Universidad Autónoma de Chile, Santiago 8910339, ChileLaboratorio de Cristalografía, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Curauma, Valparaíso 2340000, ChileDepartamento de Química, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2340000, ChileNatural brassinosteroids are widespread in the plant kingdom and it is known that they play an important role in regulating plant growth. In this study, two new brassinosteroid analogs with shorter side chains but keeping the diol function were synthesized. Thus, the synthesis of 2-deoxybrassinosteroids analogs of the 3α-hydroxy-24-nor, 22,23-dihydroxy-5α-cholestane side chain type is described. The starting material is a derivative from hyodeoxycholic acid (4), which was obtained with an overall yield of 59% following a previously reported five step route. The side chain of this intermediate was modified by oxidative decarboxylation to get a terminal olefin at the C22-C23 position (compound 20) and subsequent dihydroxylation of the olefin. The resulting epimeric mixture of 21a, 21b was separated and the absolute configuration at the C22 carbon for the main product 21a was elucidated by single crystal X-ray diffraction analysis of the benzoylated derivative 22. Finally, lactonization of 21a through a Baeyer-Villiger oxidation of triacetylated derivative 23, using CF3CO3H/CHCl3 as oxidant system, leads to lactones 24 and 25 in 35% and 14% yields, respectively. Deacetylation of these compounds leads to 2-deoxybrassinosteroids 18 and 19 in 86% and 81% yields. Full structural characterization of all synthesized compounds was achieved using their 1D, 2D NMR, and HRMS data.http://www.mdpi.com/1420-3049/23/6/1306brassinosteroid analogshyodeoxycholic acid2-deoxybrassinosteroidssynthesisshort side chain |
| spellingShingle | Rodrigo Carvajal Cesar González Andrés F. Olea Mauricio Fuentealba Luis Espinoza Synthesis of 2-Deoxybrassinosteroids Analogs with 24-nor, 22(S)-23-Dihydroxy-Type Side Chains from Hyodeoxycholic Acid Molecules brassinosteroid analogs hyodeoxycholic acid 2-deoxybrassinosteroids synthesis short side chain |
| title | Synthesis of 2-Deoxybrassinosteroids Analogs with 24-nor, 22(S)-23-Dihydroxy-Type Side Chains from Hyodeoxycholic Acid |
| title_full | Synthesis of 2-Deoxybrassinosteroids Analogs with 24-nor, 22(S)-23-Dihydroxy-Type Side Chains from Hyodeoxycholic Acid |
| title_fullStr | Synthesis of 2-Deoxybrassinosteroids Analogs with 24-nor, 22(S)-23-Dihydroxy-Type Side Chains from Hyodeoxycholic Acid |
| title_full_unstemmed | Synthesis of 2-Deoxybrassinosteroids Analogs with 24-nor, 22(S)-23-Dihydroxy-Type Side Chains from Hyodeoxycholic Acid |
| title_short | Synthesis of 2-Deoxybrassinosteroids Analogs with 24-nor, 22(S)-23-Dihydroxy-Type Side Chains from Hyodeoxycholic Acid |
| title_sort | synthesis of 2 deoxybrassinosteroids analogs with 24 nor 22 s 23 dihydroxy type side chains from hyodeoxycholic acid |
| topic | brassinosteroid analogs hyodeoxycholic acid 2-deoxybrassinosteroids synthesis short side chain |
| url | http://www.mdpi.com/1420-3049/23/6/1306 |
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