Intramolecular tandem isomerization-mannich reaction as a new route towards aminocyclopentitols

A new efficient synthetic strategy has been developed to prepare aminocyclopentitols. It is based on an iron-catalyzed tandem isomerization-Mannich reaction and uses chiral N-tert-butanesulfinamide as a chiral auxiliary. This methodology has been applied to the enantiocontrolled synthesis of a mannostatin A analogue, as well as isomers of known fucosidase and glycosidase inhibitors. New aminocyclitols are easily obtained through a short sequence including an iron-catalyzed tandem isomerization-Mannich reaction as a key step. By using N-tert-butanesulfinamides, this methodology allowed efficient enantioselective synthesis of a mannostatine A analogue and two stereoisomers of known fucosidase and glycosidase inhibitors. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.