De Novo Synthesis of a <scp>d</scp>-Galacturonic Acid Thioglycoside as Key to the Total Synthesis of a Glycosphingolipid from <i>Sphingomonas </i><i>yanoikuyae</i>
作者:Pierre Stallforth、Alexander Adibekian、Peter H. Seeberger
DOI:10.1021/ol800227b
日期:2008.4.1
A concise synthesis of a differentiallyprotected D-galacturonic acid (D-GalA) thioglycoside and the construction of a potent immunomodulating glycosphingolipid are described. The key steps of the synthesis are an Evans aldol reaction between a C4 aldehyde and a PMB-protected glycolyloxazolidinone as well as a tandem-PMB-deprotection/cyclization to thioglycosides. The key glycosylation step is optimized
De Novo Synthesis of Uronic Acid Building Blocks for Assembly of Heparin Oligosaccharides
作者:Alexander Adibekian、Pascal Bindschädler、Mattie S. M. Timmer、Christian Noti、Nina Schützenmeister、Peter H. Seeberger
DOI:10.1002/chem.200700141
日期:2007.5.25
An efficient de novo synthesis of uronic acid buildingblocks is described. The synthetic strategy relies on the stereoselective elongation of thioacetal protected dialdehydes 12 a and 17. The dialdehydes are prepared from D-xylose, a cheap and commercially available source. A highly stereoselective MgBr(2)OEt(2)-mediated Mukaiyama aldol addition to C4-aldehyde 12 a is performed to obtain D-glucuronic