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Tuning the stereoelectronic properties of 1-sulfanylhex-1-enitols for the sequential stereoselective synthesis of 2-deoxy-2-iodo-β-D-allopyranosides.
J Org Chem. 2014 Apr 04; 79(7):3060-8.JO

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.

Authors+Show Affiliations

Departament de Química Analítica i Química Orgànica, Universitat Rovira i Virgili , C/Marcel·lí Domingo s/n, 43007 Tarragona, Spain.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

24611618

Citation

Kövér, Andrea, et al. "Tuning the Stereoelectronic Properties of 1-sulfanylhex-1-enitols for the Sequential Stereoselective Synthesis of 2-deoxy-2-iodo-β-D-allopyranosides." The Journal of Organic Chemistry, vol. 79, no. 7, 2014, pp. 3060-8.
Kövér A, Boutureira O, Matheu MI, et al. Tuning the stereoelectronic properties of 1-sulfanylhex-1-enitols for the sequential stereoselective synthesis of 2-deoxy-2-iodo-β-D-allopyranosides. J Org Chem. 2014;79(7):3060-8.
Kövér, A., Boutureira, O., Matheu, M. I., Díaz, Y., & Castillón, S. (2014). Tuning the stereoelectronic properties of 1-sulfanylhex-1-enitols for the sequential stereoselective synthesis of 2-deoxy-2-iodo-β-D-allopyranosides. The Journal of Organic Chemistry, 79(7), 3060-8. https://doi.org/10.1021/jo5001912
Kövér A, et al. Tuning the Stereoelectronic Properties of 1-sulfanylhex-1-enitols for the Sequential Stereoselective Synthesis of 2-deoxy-2-iodo-β-D-allopyranosides. J Org Chem. 2014 Apr 4;79(7):3060-8. PubMed PMID: 24611618.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Tuning the stereoelectronic properties of 1-sulfanylhex-1-enitols for the sequential stereoselective synthesis of 2-deoxy-2-iodo-β-D-allopyranosides. AU - Kövér,Andrea, AU - Boutureira,Omar, AU - Matheu,M Isabel, AU - Díaz,Yolanda, AU - Castillón,Sergio, Y1 - 2014/03/21/ PY - 2014/3/12/entrez PY - 2014/3/13/pubmed PY - 2015/1/21/medline SP - 3060 EP - 8 JF - The Journal of organic chemistry JO - J. Org. Chem. VL - 79 IS - 7 N2 - 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. SN - 1520-6904 UR - https://www.unboundmedicine.com/medline/citation/24611618/Tuning_the_stereoelectronic_properties_of_1_sulfanylhex_1_enitols_for_the_sequential_stereoselective_synthesis_of_2_deoxy_2_iodo_β_D_allopyranosides_ L2 - https://dx.doi.org/10.1021/jo5001912 DB - PRIME DP - Unbound Medicine ER -