The formation of glycosides in high yield from 1-hydroxysugars using catalytic amounts (0.5mol%) of Rh(III)Cl 3 (triphos) (la) or [Rh(III)(MeCN) 3 (triphos)](TfO) 3 (1b) is described. High stereocontrol at the anomeric center is achieved by neighboring group participation. In addition, an application of this new glycosylation procedure for the synthesis of a derivative of the oviposition-deterring
Taurinderivate, Verfahren zu deren Herstellung und deren Verwendung
申请人:CIBA-GEIGY AG
公开号:EP0474590A2
公开(公告)日:1992-03-11
Verbindung der Formel I
in Form ihrer optischen Isomeren (8R) oder (8S) oder deren Gemische, sowie ihre Alkalimetall- und Erdalkalimetallsalze eignen sich zum Schützen von Kirschen gegen den Befall mit Kirschenfliegen.
式 I 的化合物
的光学异构体(8R)或(8S)或其混合物形式的化合物及其碱金属盐和碱土金属盐适用于保护樱桃免受樱桃蝇的侵扰。
Towards oligosaccharide libraries: A study of the random galactosylation of unprotected N-acetylglucosamine
作者:Yili Ding、Jill Labbe、Osamu Kanie、Ole Hindsgaul
DOI:10.1016/0968-0896(96)00064-8
日期:1996.5
A single reaction of an unprotected beta-D-GlcNAc glycoside with tetra-O-acetyl-alpha-D-galactopyranosyl trichloroacetimidate in dioxane, catalyzed by BF3-etherate, was shown to yield all six possible Gal-GlcNAc disaccharides. This result is surprising not only because significant amounts of alpha-linked disaccharides were formed, despite the presence of a participating group at O-2 of the glycosyl donor, but also because glycosylation of the primary OH-6 is not the dominant reaction. These results suggest 'random-glycosylation' to be a valid strategy for the rapid production of oligosaccharide libraries. Copyright (C) 1996 Elsevier Science Ltd.