Indium-mediated C-allylation of melibiose

• Main Authors: Christian Denner, Manuel Gintner, Hanspeter Kählig, Walther Schmid
• Format: Article
• Language: English
• Published: Beilstein-Institut 2019-10-01
• Series: Beilstein Journal of Organic Chemistry
• Subjects: carbohydrates; c–c bond formation; indium-mediated allylation; melibiose; ozonolysis
• Online Access: https://doi.org/10.3762/bjoc.15.238

The indium-mediated allylation reaction has been applied to melibiose, a disaccharidic substrate. This elongation methodology allows for a short, efficient and diastereoselective approach towards complex glycosylated carbohydrate structures. The stereochemical outcome of the key intermediates, allylated disaccharides, has been determined by X-ray analysis. Ozonolysis of the introduced double bond yielded the unprotected elongated disaccharides in the equilibrium of the pyranoid as well as furanoid isomers in both anomeric forms, respectively. Per-O-acetylation has been performed to facilitate separation of the isomeric mixture for structural identification. The main product revealed to adopt a β-pyranoid form of the elongated unit at the reducing end of the disaccharide.