ChemInform Abstract: Stereoselective 1,2-cis-Galactosylation Assisted by Remote Neighboring Group Participation and Solvent Effects.

✍ Scribed by Alexei V. Demchenko; Emmanuel Rousson; Geert-Jan Boons

• Publisher: John Wiley and Sons
• Year: 2010
• Weight: 36 KB
• Volume: 30
• Category: Article
• ISSN: 0931-7597
• DOI: 10.1002/chin.199950200

✦ Synopsis

Stereoselective 1,2-cis-Galactosylation Assisted by Remote Neighboring Group Participation and Solvent Effects.

-It is demonstrated that the α-selectivity in glycosylations of acceptors (II) or (IV) with D-galactosyl donors of type (I) can be significantly improved by using donors bearing a neighboring group participating functionality at C-4. The best results are obtained with the electron-donating p-anisoyl ester moiety of derivative (If), which reacts with acceptors (IV) to give disaccharides with excellent anomeric stereoselectivities. The α-selectivity can be further improved by use of dioxane/toluene as solvent instead of Et 2 O/CH 2 Cl-CH 2 Cl. -(DEMCHENKO,