Readily available carbohydrate-derived imines and amides as chiral ligands for asymmetric

An easy and diastereoselective strategy for the synthesis of a new tetrahydrofuranic chiral aldehyde and a new tetrahydrofuranic acid derived from D-ribose is reported. These compounds have been shown to be useful starting materials for obtaining a never described before class of iminic- and amidic-carbohydrate based chiral ligands, endowed with stability to purification on silica flash column and to storage, and characterized by the presence of a stereogenic center alpha to the iminic or amidic bond. The first results obtained from the application of these chiral ligands in a model reaction, conjugate addition of Et2Zn to cyclohexenone, are discussed