152844-41-2Relevant academic research and scientific papers
Synthesis of novel analogues of the calicheamicin γ1 and esperamicin A1B oligosaccharides
Moutel, Stephane,Prandi, Jacques
, p. 305 - 315 (2007/10/03)
The chemical synthesis of three analogues of the calicheamicin γ1 and esperamicin A1B 2 oligosaccharides is described in which the carbohydrate ring E is replaced by a basic side chain E'. Our synthetic strategy begins with ABE' fragment construction which possesses an unusual β N-O glycosidic bond. Glycosylation of the nitrone 20 and the appropriate activated sugar B 13 or 22 gives the disaccharides 23 and 24 respectively. Esperamicin A1B oligosaccharide analogue 5 is obtained after two deprotection steps of the fragment 24. After removal of the protecting groups of unit 23, the fully deprotected disulfide 33 is reduced and immediately coupled with the deprotected aromatic unit C 30 (or CD 31) to provide the calicheamicin γ1 oligosaccharide analogues 3 and 4. We also report the synthesis of hemiacetal 7 in which the thioester function between the CD and B rings is replaced by an ester linkage. This arylsaccharide is a key intermediate required for the synthesis of a novel calicheamicin γ1 analogue 6.
Synthesis of 2,6-Dideoxy-4-S-Methyl-4-Thio-D-ribo-Hexopyranose, A Component of the Esperamicin Oligosaccharide
Dupradeau, Francois-Yves,Prandi, Jacques,Beau, Jean-Marie
, p. 3205 - 3220 (2007/10/02)
Two synthetic approaches to 2,6-dideoxy-4-S-methyl-4-thio-D-ribo pyranose, a component of the oligosaccharide of esperamicins are described.An asymmetric synthesis, starting from the propargylic alcohol dimer, relies on the Sharpless asymmetric epoxidation and the regioselective opening of epoxy alcohols.The other synthesis is based on stereocontrolled transformations of a readily available sugar precursor, D-galactose.
