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Indium- and Zinc-Mediated Acyloxyallylation of Protected and Unprotected Aldotetroses—Revealing a Pronounced Diastereodivergence and a Fundamental Difference in the Performance of the Mediating Metal
[Image: see text] The acyloxyallylation of unprotected aldoses was first demonstrated more than a decade ago as a potentially elegant two-carbon homologation of reducing sugars (upon ozonolysis); however, its application in real case syntheses remained scarce. Following up on such a successful showc...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical
Society
2018
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5838623/ https://www.ncbi.nlm.nih.gov/pubmed/29369620 http://dx.doi.org/10.1021/acs.joc.7b03063 |
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author | Draskovits, Markus Stanetty, Christian Baxendale, Ian R. Mihovilovic, Marko D. |
author_facet | Draskovits, Markus Stanetty, Christian Baxendale, Ian R. Mihovilovic, Marko D. |
author_sort | Draskovits, Markus |
collection | PubMed |
description | [Image: see text] The acyloxyallylation of unprotected aldoses was first demonstrated more than a decade ago as a potentially elegant two-carbon homologation of reducing sugars (upon ozonolysis); however, its application in real case syntheses remained scarce. Following up on such a successful showcase and to answer several pending questions about this attractive transformation, we engaged in an in depth methodological reinvestigation. The epimeric tetroses l-erythrose and d-threose in unprotected and protected form were successfully applied to the indium and also zinc-mediated acyloxyallylation, with the latter being a first for an unprotected sugar. The investigation largely benefited from the choice of these more exotic starting materials as it allowed unambiguous identification/quantification of the hexose-products which are available as authentic reference materials. The observed diastereoselectivities indicate a strong substrate control (stereochemistry at O2), and the influence of the reagent’s structure on the selectivity was investigated in great detail. A strong facial diastereodivergence between related protected and unprotected structures was demonstrated and an unexpected, pronounced principle difference in performance between indium and zinc was revealed. |
format | Online Article Text |
id | pubmed-5838623 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | American Chemical
Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-58386232018-03-07 Indium- and Zinc-Mediated Acyloxyallylation of Protected and Unprotected Aldotetroses—Revealing a Pronounced Diastereodivergence and a Fundamental Difference in the Performance of the Mediating Metal Draskovits, Markus Stanetty, Christian Baxendale, Ian R. Mihovilovic, Marko D. J Org Chem [Image: see text] The acyloxyallylation of unprotected aldoses was first demonstrated more than a decade ago as a potentially elegant two-carbon homologation of reducing sugars (upon ozonolysis); however, its application in real case syntheses remained scarce. Following up on such a successful showcase and to answer several pending questions about this attractive transformation, we engaged in an in depth methodological reinvestigation. The epimeric tetroses l-erythrose and d-threose in unprotected and protected form were successfully applied to the indium and also zinc-mediated acyloxyallylation, with the latter being a first for an unprotected sugar. The investigation largely benefited from the choice of these more exotic starting materials as it allowed unambiguous identification/quantification of the hexose-products which are available as authentic reference materials. The observed diastereoselectivities indicate a strong substrate control (stereochemistry at O2), and the influence of the reagent’s structure on the selectivity was investigated in great detail. A strong facial diastereodivergence between related protected and unprotected structures was demonstrated and an unexpected, pronounced principle difference in performance between indium and zinc was revealed. American Chemical Society 2018-01-25 2018-03-02 /pmc/articles/PMC5838623/ /pubmed/29369620 http://dx.doi.org/10.1021/acs.joc.7b03063 Text en Copyright © 2018 American Chemical Society This is an open access article published under a Creative Commons Attribution (CC-BY) License (http://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.html) , which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited. |
spellingShingle | Draskovits, Markus Stanetty, Christian Baxendale, Ian R. Mihovilovic, Marko D. Indium- and Zinc-Mediated Acyloxyallylation of Protected and Unprotected Aldotetroses—Revealing a Pronounced Diastereodivergence and a Fundamental Difference in the Performance of the Mediating Metal |
title | Indium- and Zinc-Mediated
Acyloxyallylation of Protected
and Unprotected Aldotetroses—Revealing a Pronounced Diastereodivergence
and a Fundamental Difference in the Performance of the Mediating Metal |
title_full | Indium- and Zinc-Mediated
Acyloxyallylation of Protected
and Unprotected Aldotetroses—Revealing a Pronounced Diastereodivergence
and a Fundamental Difference in the Performance of the Mediating Metal |
title_fullStr | Indium- and Zinc-Mediated
Acyloxyallylation of Protected
and Unprotected Aldotetroses—Revealing a Pronounced Diastereodivergence
and a Fundamental Difference in the Performance of the Mediating Metal |
title_full_unstemmed | Indium- and Zinc-Mediated
Acyloxyallylation of Protected
and Unprotected Aldotetroses—Revealing a Pronounced Diastereodivergence
and a Fundamental Difference in the Performance of the Mediating Metal |
title_short | Indium- and Zinc-Mediated
Acyloxyallylation of Protected
and Unprotected Aldotetroses—Revealing a Pronounced Diastereodivergence
and a Fundamental Difference in the Performance of the Mediating Metal |
title_sort | indium- and zinc-mediated
acyloxyallylation of protected
and unprotected aldotetroses—revealing a pronounced diastereodivergence
and a fundamental difference in the performance of the mediating metal |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5838623/ https://www.ncbi.nlm.nih.gov/pubmed/29369620 http://dx.doi.org/10.1021/acs.joc.7b03063 |
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