General Three Carbon Chiral Synthons from Carbohydrates: Chiral Pool and Chiral Auxiliary Approaches

The use of carbohydrates to gain access to chiral 3-carbon synthons for use in applications including pharmaceuticals, agrichemicals, biomaterials and certain advanced materials is discussed. Three basic approaches are described. The first one is based on the direct scission of carbohydrates to yield 3- carbon synthons directly, the second on 1 carbon degradation reactions on optically pure 3-hydroxy-γ-butyrolactones or their derivatives and the third approach is based on the use of carbohydrates as chiral auxiliaries to induce chirality into prochiral substrates. Because of the general availability of optically pure 3-hydroxy-γ-butyrolactones on commercial scale and the ease of the transformations, the second approach has several practical advantages and represents a significant step forward our drive to develop a general carbohydrate-based chemistry platform.