A series of benzylated monosaccharidic PSE acetals undergoes regioselective TIBAL-mediated de-O-benzylation, to afford monobenzyl ethers, readily available as buildingblocks for oligosaccharidessynthesis.
Expeditious synthesis of β-cycloacetalic sulfoxides. Introducing 1-phenylsulfinyl-2-phenylsulfanylethylene (SOSE), a promising new alkenylsulfur reagent
作者:Elena Cabianca、Arnaud Tatibouët、Fabrizio Fabris、Ottorino De Lucchi、Patrick Rollin
DOI:10.1016/j.tetlet.2004.11.151
日期:2005.2
In similarity with the strongly electrophilic BPSEs and despite its more electron-rich character, 1-phenylsulfinyl-2-phenylsulfanylethylene (SOSE) reacts with nucleophiles with displacement of the phenylthio moiety. Specifically it reacts with diols under basic conditions to produce beta-cycloacetalic sulfoxides. The reaction has been amply developed in carbohydrate chemistry. (C) 2004 Elsevier Ltd. All rights reserved.
Carbohydrate-derived PSE acetals: controlled base-induced ring cleavage
作者:Florence Chéry、Elena Cabianca、Arnaud Tatibouët、Ottorino De Lucchi、Patrick Rollin
DOI:10.1016/j.tet.2011.11.009
日期:2012.1
Retro-Michael type reactions applied to PSE acetals protecting monosaccharides led either to complete removal or to ring-cleavage. In protic medium, application of standard basic conditions resulted in acetal deprotection, while the use of butyl lithium in aprotic medium allowed controlled ring-cleavage. A regio-and stereoselective C- over O-alkylation was observed during the process. Furthermore, depending on the substrates and the reaction conditions involved, new carbohydrate-derived beta-alkoxyvinyl sulfones were obtained with varying regioselectivity. (C) 2011 Elsevier Ltd. All rights reserved.
FRASER-REID, BERT;MOLINO, BRUCE F.;MAGDZINSKI, LEON;MOOTOO, DAVID R., J. ORG. CHEM., 52,(1987) N 20, 4505-4511
作者:FRASER-REID, BERT、MOLINO, BRUCE F.、MAGDZINSKI, LEON、MOOTOO, DAVID R.