653575-97-4Relevant academic research and scientific papers
Tuning the stereoelectronic properties of 1-sulfanylhex-1-enitols for the sequential stereoselective synthesis of 2-deoxy-2-iodo-β- d -allopyranosides
K?vér, Andrea,Boutureira, Omar,Matheu, M. Isabel,Díaz, Yolanda,Castillón, Sergio
, p. 3060 - 3068 (2014/05/06)
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.
Stereoselective synthesis of 2-deoxy-2-iodo-glycosides from furanoses. A new route to 2-deoxy-glycosides and 2-deoxy-oligosaccharides of ribo and xylo configuration
Rodriguez, Miguel Angel,Boutureira, Omar,Arnes, Xavier,Matheu, M. Isabel,Diaz, Yolanda,Castillon, Sergio
, p. 10297 - 10310 (2007/10/03)
A general procedure for the stereoselective synthesis of 2-deoxy-2-iodo-hexo- and -hepto-pyranosyl glycosides from furanoses is reported. The proposed methodology provides a new route for accessing 2-deoxy-oligosaccharides. The procedure involves three re
Wittig approach to carbohydrate-derived vinyl sulfides, new substrates for regiocontrolled ring-closure reactions
Aucagne, Vincent,Tatibou?t, Arnaud,Rollin, Patrick
, p. 1817 - 1826 (2007/10/03)
Reaction of methyl- and phenylthiomethylidene phosphoranes 1 and 2 with a variety of reducing sugars has been explored. Furano-type carbohydrates afforded with good yields the corresponding open-chain vinyl sulfides, whereas pyrano derivatives produced elimination compounds together with the expected vinyl sulfides, depending on the nature of the protective groups.
Phenyl 2-Deoxy-2-iodo-1-thio-glycosides: New Glycosyl Donors for the Stereo-selective Synthesis of 2-Deoxy-oligosaccharides
Arnés, Xavier,Díaz, Yolanda,Castillón, Sergio
, p. 2143 - 2146 (2007/10/03)
Phenyl 2-deoxy-2-iodo-1-thioglycosides, prepared from simple pentoses by olefination and iodine-induced cyclization, have proved to be efficient glycosyl donors for the stereoselective synthesis of 2-deoxy-2-iodo- oligosaccharides, which are precursors of
