Autor segons l'article: M. Isabel Matheu Andrea Kövér Omar Boutureira Yolanda Díaz Sergio Castillón
Departament: Química Analítica i Química Orgànica
Autor/s de la URV: MATHEU MALPARTIDA, MARÍA ISABEL Andrea Kövér Omar Boutureira Yolanda Díaz Sergio Castillón
Paraules clau: deoxycarbohydrates
Resum: 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.
Grup de recerca: Síntesis Orgànica Estereoselectiva
Àrees temàtiques: Química Química Chemistry
Accès a la llicència d'ús: https://creativecommons.org/licenses/by/3.0/es/
ISSN: 0022-3263
Identificador de l'autor: 0000-0001-5216-9260 n/a 0000-0002-0768-8309 0000-0001-5567-8108 n/a
Data d'alta del registre: 2015-04-16
Pàgina final: 3068
Volum de revista: 79
Versió de l'article dipositat: info:eu-repo/semantics/acceptedVersion
Enllaç font original: https://pubs.acs.org/doi/10.1021/jo5001912
URL Document de llicència: https://repositori.urv.cat/ca/proteccio-de-dades/
DOI de l'article: 10.1021/jo5001912
Entitat: Universitat Rovira i Virgili
Any de publicació de la revista: 2014
Pàgina inicial: 3060
Tipus de publicació: Article Artículo Article