An Enantiospecific Synthesis of 5-<i>epi</i>-α-Bulnesene
As a result of its unique fragrance and wider role in traditional medicine, agarwood produced in <i>Aquilaria</i> spp. and certain other trees has been harvested to near extinction as a natural phenomenon. Artificially induced agarwood production in <i>Aquilaria</i> plantatio...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-05-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/28/9/3900 |
| _version_ | 1797602080567853056 |
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| author | Jiarui Zong Jeremy Robertson |
| author_facet | Jiarui Zong Jeremy Robertson |
| author_sort | Jiarui Zong |
| collection | DOAJ |
| description | As a result of its unique fragrance and wider role in traditional medicine, agarwood produced in <i>Aquilaria</i> spp. and certain other trees has been harvested to near extinction as a natural phenomenon. Artificially induced agarwood production in <i>Aquilaria</i> plantations has sated some of the demand although the product quality is variable. Synthetic chemistry may have a role to play in providing sustainable routes to many of the fragrant components identified in agarwood and its smoke when burnt as incense. In this work, we report efforts towards a total synthesis of the guaiane sesquiterpene α-bulnesene, which is found, along with its more fragrant oxidised derivatives, in agarwood. Following the ring-expansion of (<i>R</i>)-carvone using reported procedures, α-butenylation gave a substrate for samarium diiodide mediated reductive cyclisation, the two butenyl epimers of the substrate each leading to a single bicyclic alcohol (<b>24</b> and <b>25</b>). Overall homoconjugate hydride reduction of one of these alcohols was achieved by Lewis acid-mediated ionisation and then hydride transfer from triethylsilane to complete an overall seven-step synthesis of 5-<i>epi</i>-α-bulnesene. This new synthesis paves the way for short routes to both α-bulnesene enantiomers and a study of their aerial and enzymatic oxidation products. |
| first_indexed | 2024-03-11T04:11:55Z |
| format | Article |
| id | doaj.art-2ad1341264184447bf1bab4a875c78e6 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-11T04:11:55Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-2ad1341264184447bf1bab4a875c78e62023-11-17T23:24:59ZengMDPI AGMolecules1420-30492023-05-01289390010.3390/molecules28093900An Enantiospecific Synthesis of 5-<i>epi</i>-α-BulneseneJiarui Zong0Jeremy Robertson1Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, UKChemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, UKAs a result of its unique fragrance and wider role in traditional medicine, agarwood produced in <i>Aquilaria</i> spp. and certain other trees has been harvested to near extinction as a natural phenomenon. Artificially induced agarwood production in <i>Aquilaria</i> plantations has sated some of the demand although the product quality is variable. Synthetic chemistry may have a role to play in providing sustainable routes to many of the fragrant components identified in agarwood and its smoke when burnt as incense. In this work, we report efforts towards a total synthesis of the guaiane sesquiterpene α-bulnesene, which is found, along with its more fragrant oxidised derivatives, in agarwood. Following the ring-expansion of (<i>R</i>)-carvone using reported procedures, α-butenylation gave a substrate for samarium diiodide mediated reductive cyclisation, the two butenyl epimers of the substrate each leading to a single bicyclic alcohol (<b>24</b> and <b>25</b>). Overall homoconjugate hydride reduction of one of these alcohols was achieved by Lewis acid-mediated ionisation and then hydride transfer from triethylsilane to complete an overall seven-step synthesis of 5-<i>epi</i>-α-bulnesene. This new synthesis paves the way for short routes to both α-bulnesene enantiomers and a study of their aerial and enzymatic oxidation products.https://www.mdpi.com/1420-3049/28/9/3900agarwoodincensefragrancessesquiterpenesα-bulnesenenatural products |
| spellingShingle | Jiarui Zong Jeremy Robertson An Enantiospecific Synthesis of 5-<i>epi</i>-α-Bulnesene Molecules agarwood incense fragrances sesquiterpenes α-bulnesene natural products |
| title | An Enantiospecific Synthesis of 5-<i>epi</i>-α-Bulnesene |
| title_full | An Enantiospecific Synthesis of 5-<i>epi</i>-α-Bulnesene |
| title_fullStr | An Enantiospecific Synthesis of 5-<i>epi</i>-α-Bulnesene |
| title_full_unstemmed | An Enantiospecific Synthesis of 5-<i>epi</i>-α-Bulnesene |
| title_short | An Enantiospecific Synthesis of 5-<i>epi</i>-α-Bulnesene |
| title_sort | enantiospecific synthesis of 5 i epi i α bulnesene |
| topic | agarwood incense fragrances sesquiterpenes α-bulnesene natural products |
| url | https://www.mdpi.com/1420-3049/28/9/3900 |
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