Synthesis of Furanosyl C-1 Glycals Through Palladium-Catalyzed Reactions of a Furanosyl 2,3-Anhydro-exo-glycal.

A furanose-derived 2,3-anhydro-exo-glycal, readily available from D-mannose in four steps, has proven to be a useful substrate in the preparation of a variety of highly functionalized C-1 glycals. Upon treatment with Pd0 it affords a π-allyl palladium complex that can react with nucleophiles such as amines, ethyl malonate, or vinylstannanes. On the other hand, umpolung of the π-allyl palladium complex with Et2Zn facilitates its reaction with electrophilic aldehydes and ketones.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)