Imino-sugars by Stereoselective Processes Employing Pyrroline N-oxides

The total synthesis of natural products requires selective methods to adapt to the structural complexity the nature has introduced in natural compounds. From this challenge derives the impetus to find new reactions, new reagents and new catalysts to run reactions in a chemoselective, regioselective and stereoselective way. Recently, domino or multicomponent,1 combinatorial2 or enzymatic3 processes, have expanded the synthetic tools available to researchers, and topics like atom economy4 and environmentally friendly syntheses became the concern of organic chemists. Having in mind all these points we approached the synthesis of natural products like glycosidase inhibitors,7 belonging to the classes of indolizine5 and pyrrolizine6 alkaloids, which are attracting growing interest from synthetic chemists for their various and essential biological activities