Synthesis 2008(4): 519-526  
DOI: 10.1055/s-2008-1032150
PAPER
© Georg Thieme Verlag Stuttgart · New York

Efficient Synthesis of Glycosylated Asparaginic Acid Building Blocks via Click Chemistry

Nikolas Pietrzik, Carsten Schips, Thomas Ziegler*
Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
Fax: +49(7071)295244; e-Mail: thomas.ziegler@uni-tuebingen.de;
Further Information

Publication History

Received 16 August 2007
Publication Date:
31 January 2008 (online)

Abstract

A series of per-O-acetyl-glycose-Fmoc-l-Asp(O-t-Bu) derivatives and tert-butyl per-O-acetyl-glycose-(S)-3-fluorenyl­methyloxycarbamidobutyrates were prepared by copper-catalyzed 1,3-dipolar cycloaddition of fully acetylated propargyl 1-thioglycosides (gluco, galacto, manno and rhamno series) and Fmoc-l-Asp(O-t-Bu)propargyl amide with tert-butyl (S)-4-azido-3-fluorenylmethyloxycarbamidobutyrate, 2,3,4,6-tri-O-acetyl-glycosyl azides and ethyl 2,3,4-tri-O-acetyl-6-azido-6-deoxy-1-thioglycosides (gluco, galacto, manno series), respectively (click chemistry). Thus obtained orthogonally protected l-asparaginic and (S)-3-aminobutyric acids bearing an acetyl-protected glycose or glycoside moiety, linked through a triazole spacer, are suitable building blocks for combinatorial glycopeptide syntheses.