617698-86-9Relevant academic research and scientific papers
Solid-phase synthesis of a phytoalexin elicitor pentasaccharide using a 4-azido-3-chlorobenzyl group as the key for temporary protection and catch-and-release purification
Egusa, Kenji,Kusumoto, Shoichi,Fukase, Koichi
, p. 3435 - 3445 (2007/10/03)
A phytoalexin elicitor pentasaccharide of the rice blast disease fungus, Pyricularia oryzae, was synthesized by a new route involving a solid-phase method, in which a 4-azido-3-chlorobenzyl (ClAzb) group was used for temporary protection of the hydroxy functions and catch-and-release purification. Thioglycosides possessing the ClAzb group were used as glycosyl donors and a macroporous polystyrene as a solid support. The saccharide chain was elongated by repeating a set of reactions: removal of the ClAzb group, glycosylation and capping of the unglycosylated hydroxy groups. Cleavage from the solid support by treatment with sodium methoxide afforded a crude pentasaccharide possessing the ClAzb group as a tag. The pentasaccharide was then purified by a catch-and-release procedure based on the specific reaction between the azido group and a solid-supported phosphane. The final deprotection of all benzyl-type protective groups gave the desired phytoalexin elicitor pentasaccharide 1 in overall 15% yield (from a solid-supported monosaccharide 4, average yield of 81% for each of a total of nine steps). The characteristic peaks of the azido group in the infrared spectrum were also useful for monitoring reactions in the solid phase. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
