Articles producció científica> Química Analítica i Química Orgànica

Tuning the Stereoelectronic Properties of 1-Sulfanylhex-1-enitols for the Sequential Stereoselective Synthesis of 2-Deoxy-2-iodo-ß-D-allopyranoside

  • Identification data

    Identifier: PC:1156
    Authors:
    M. Isabel MatheuAndrea KövérOmar BoutureiraYolanda DíazSergio Castillón
    Abstract:
    The preparation of challenging 2-deoxy-2-iodo-β-D-allo precursors of 2-deoxy-β-D-ribo-hexopyranosyl units and other analogues is reported using a robust olefination−cyclization−glycosylation sequence. Here, we particularly focus on tuning the stereoelectronic properties of the alkenyl sulfides intermediates in order to improve the diastereoselectivity of the cyclization step and, hence, the efficiency of the overall transformation. Phosphine oxides with the general formula Ph2P(O)CH2SR (R = t- Bu, Cy, p-MeOPh, 2,6-di-ClPh, and 2,6-di-MePh) were easily synthesized and subsequently used in the olefination reaction with 2,3,5-tri-O-benzyl-D-ribose and -D-arabinose. The corresponding sugar-derived alkenyl sulfides were submitted to a 6-endo [I+]- induced cyclization, and the resulting 2-deoxy 2-iodohexopyranosyl-1-thioglycosides were used as glycosyl donors for the stereoselective synthesis of 2-deoxy-2-iodohexopyranosyl glycosides. Among the different S-groups studied, t-Bu derivative was the best performer for the synthesis of cholesteryl 2-deoxy-2-iodomannopyranosides, whereas for the synthesis of 2-deoxy-2- iodoallopyranosides none of the derivatives here studied proved superior to the phenyl analogue previously described. Glycosylation of cholesterol with different D-allo and D-manno derivatives produced 2-deoxy-2-iodoglycosides with stereoselectivities in the same order in each case, reinforcing the involvement of an oxocarbenium ion as the common intermediate of this crucial glycosylation step.
  • Others:

    Author, as appears in the article.: M. Isabel Matheu Andrea Kövér Omar Boutureira Yolanda Díaz Sergio Castillón
    Department: Química Analítica i Química Orgànica
    URV's Author/s: MATHEU MALPARTIDA, MARÍA ISABEL Andrea Kövér Omar Boutureira Yolanda Díaz Sergio Castillón
    Keywords: deoxycarbohydrates
    Abstract: The preparation of challenging 2-deoxy-2-iodo-β-D-allo precursors of 2-deoxy-β-D-ribo-hexopyranosyl units and other analogues is reported using a robust olefination−cyclization−glycosylation sequence. Here, we particularly focus on tuning the stereoelectronic properties of the alkenyl sulfides intermediates in order to improve the diastereoselectivity of the cyclization step and, hence, the efficiency of the overall transformation. Phosphine oxides with the general formula Ph2P(O)CH2SR (R = t- Bu, Cy, p-MeOPh, 2,6-di-ClPh, and 2,6-di-MePh) were easily synthesized and subsequently used in the olefination reaction with 2,3,5-tri-O-benzyl-D-ribose and -D-arabinose. The corresponding sugar-derived alkenyl sulfides were submitted to a 6-endo [I+]- induced cyclization, and the resulting 2-deoxy 2-iodohexopyranosyl-1-thioglycosides were used as glycosyl donors for the stereoselective synthesis of 2-deoxy-2-iodohexopyranosyl glycosides. Among the different S-groups studied, t-Bu derivative was the best performer for the synthesis of cholesteryl 2-deoxy-2-iodomannopyranosides, whereas for the synthesis of 2-deoxy-2- iodoallopyranosides none of the derivatives here studied proved superior to the phenyl analogue previously described. Glycosylation of cholesterol with different D-allo and D-manno derivatives produced 2-deoxy-2-iodoglycosides with stereoselectivities in the same order in each case, reinforcing the involvement of an oxocarbenium ion as the common intermediate of this crucial glycosylation step.
    Research group: Síntesis Orgànica Estereoselectiva
    Thematic Areas: Química Química Chemistry
    licence for use: https://creativecommons.org/licenses/by/3.0/es/
    ISSN: 0022-3263
    Author identifier: 0000-0001-5216-9260 n/a 0000-0002-0768-8309 0000-0001-5567-8108 n/a
    Record's date: 2015-04-16
    Last page: 3068
    Journal volume: 79
    Papper version: info:eu-repo/semantics/acceptedVersion
    Link to the original source: https://pubs.acs.org/doi/10.1021/jo5001912
    Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
    Article's DOI: 10.1021/jo5001912
    Entity: Universitat Rovira i Virgili
    Journal publication year: 2014
    First page: 3060
    Publication Type: Article Artículo Article
  • Keywords:

    Esterificació
    Estereoquímica
    Carbohidrats
    deoxycarbohydrates
    Química
    Química
    Chemistry
    0022-3263
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