Synthesis of Four Orthogonally Protected Rare <span style="font-variant: small-caps">l</span>-Hexose Thioglycosides from <span style="font-variant: small-caps">d</span>-Mannose by C-5 and C-4 Epimerization

<span style="font-variant: small-caps;">l</span>-Hexoses are important components of biologically relevant compounds and precursors of some therapeuticals. However, they typically cannot be obtained from natural sources and due to the complexity of their synthesis, their commer...

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Main Authors: Fruzsina Demeter, Ilona Bereczki, Anikó Borbás, Mihály Herczeg
Format: Article
Language:English
Published: MDPI AG 2022-05-01
Series:Molecules
Subjects:
Online Access:https://www.mdpi.com/1420-3049/27/11/3422
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author Fruzsina Demeter
Ilona Bereczki
Anikó Borbás
Mihály Herczeg
author_facet Fruzsina Demeter
Ilona Bereczki
Anikó Borbás
Mihály Herczeg
author_sort Fruzsina Demeter
collection DOAJ
description <span style="font-variant: small-caps;">l</span>-Hexoses are important components of biologically relevant compounds and precursors of some therapeuticals. However, they typically cannot be obtained from natural sources and due to the complexity of their synthesis, their commercially available derivatives are also very expensive. Starting from one of the cheapest <span style="font-variant: small-caps;">d</span>-hexoses, <span style="font-variant: small-caps;">d</span>-mannose, using inexpensive and readily available chemicals, we developed a reaction pathway to obtain two orthogonally protected <span style="font-variant: small-caps;">l</span>-hexose thioglycoside derivatives, <span style="font-variant: small-caps;">l</span>-gulose and <span style="font-variant: small-caps;">l</span>-galactose, through the corresponding 5,6-unsaturated thioglycosides by C-5 epimerization. From these derivatives, the orthogonally protected thioglycosides of further two <span style="font-variant: small-caps;">l</span>-hexoses (<span style="font-variant: small-caps;">l</span>-allose and <span style="font-variant: small-caps;">l</span>-glucose) were synthesized by C-4 epimerization. The preparation of the key intermediates, the 5,6-unsaturated derivatives, was systematically studied using various protecting groups. By the method developed, we are able to produce highly functionalized <span style="font-variant: small-caps;">l</span>-gulose derivatives in 9 steps (total yields: 21–23%) and <span style="font-variant: small-caps;">l</span>-galactose derivatives in 12 steps (total yields: 6–8%) starting from <span style="font-variant: small-caps;">d</span>-mannose.
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spelling doaj.art-84126e5cb6f44c3289ad778540c1874c2023-11-23T14:28:30ZengMDPI AGMolecules1420-30492022-05-012711342210.3390/molecules27113422Synthesis of Four Orthogonally Protected Rare <span style="font-variant: small-caps">l</span>-Hexose Thioglycosides from <span style="font-variant: small-caps">d</span>-Mannose by C-5 and C-4 EpimerizationFruzsina Demeter0Ilona Bereczki1Anikó Borbás2Mihály Herczeg3Department of Pharmaceutical Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, HungaryDepartment of Pharmaceutical Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, HungaryDepartment of Pharmaceutical Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, HungaryDepartment of Pharmaceutical Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary<span style="font-variant: small-caps;">l</span>-Hexoses are important components of biologically relevant compounds and precursors of some therapeuticals. However, they typically cannot be obtained from natural sources and due to the complexity of their synthesis, their commercially available derivatives are also very expensive. Starting from one of the cheapest <span style="font-variant: small-caps;">d</span>-hexoses, <span style="font-variant: small-caps;">d</span>-mannose, using inexpensive and readily available chemicals, we developed a reaction pathway to obtain two orthogonally protected <span style="font-variant: small-caps;">l</span>-hexose thioglycoside derivatives, <span style="font-variant: small-caps;">l</span>-gulose and <span style="font-variant: small-caps;">l</span>-galactose, through the corresponding 5,6-unsaturated thioglycosides by C-5 epimerization. From these derivatives, the orthogonally protected thioglycosides of further two <span style="font-variant: small-caps;">l</span>-hexoses (<span style="font-variant: small-caps;">l</span>-allose and <span style="font-variant: small-caps;">l</span>-glucose) were synthesized by C-4 epimerization. The preparation of the key intermediates, the 5,6-unsaturated derivatives, was systematically studied using various protecting groups. By the method developed, we are able to produce highly functionalized <span style="font-variant: small-caps;">l</span>-gulose derivatives in 9 steps (total yields: 21–23%) and <span style="font-variant: small-caps;">l</span>-galactose derivatives in 12 steps (total yields: 6–8%) starting from <span style="font-variant: small-caps;">d</span>-mannose.https://www.mdpi.com/1420-3049/27/11/3422<span style="font-variant: small-caps">l</span>-hexosesthioglycosidesepimerizationeliminationhydroboration
spellingShingle Fruzsina Demeter
Ilona Bereczki
Anikó Borbás
Mihály Herczeg
Synthesis of Four Orthogonally Protected Rare <span style="font-variant: small-caps">l</span>-Hexose Thioglycosides from <span style="font-variant: small-caps">d</span>-Mannose by C-5 and C-4 Epimerization
Molecules
<span style="font-variant: small-caps">l</span>-hexoses
thioglycosides
epimerization
elimination
hydroboration
title Synthesis of Four Orthogonally Protected Rare <span style="font-variant: small-caps">l</span>-Hexose Thioglycosides from <span style="font-variant: small-caps">d</span>-Mannose by C-5 and C-4 Epimerization
title_full Synthesis of Four Orthogonally Protected Rare <span style="font-variant: small-caps">l</span>-Hexose Thioglycosides from <span style="font-variant: small-caps">d</span>-Mannose by C-5 and C-4 Epimerization
title_fullStr Synthesis of Four Orthogonally Protected Rare <span style="font-variant: small-caps">l</span>-Hexose Thioglycosides from <span style="font-variant: small-caps">d</span>-Mannose by C-5 and C-4 Epimerization
title_full_unstemmed Synthesis of Four Orthogonally Protected Rare <span style="font-variant: small-caps">l</span>-Hexose Thioglycosides from <span style="font-variant: small-caps">d</span>-Mannose by C-5 and C-4 Epimerization
title_short Synthesis of Four Orthogonally Protected Rare <span style="font-variant: small-caps">l</span>-Hexose Thioglycosides from <span style="font-variant: small-caps">d</span>-Mannose by C-5 and C-4 Epimerization
title_sort synthesis of four orthogonally protected rare span style font variant small caps l span hexose thioglycosides from span style font variant small caps d span mannose by c 5 and c 4 epimerization
topic <span style="font-variant: small-caps">l</span>-hexoses
thioglycosides
epimerization
elimination
hydroboration
url https://www.mdpi.com/1420-3049/27/11/3422
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