Asymmetric Synthesis

 

A novel entiaoselective synthesis of chiral QUINAP is described. Hereby, the seperation of the disastereomers was achived by the preparation and simple chromatographic seperation of chiral sulfoxide intermediates. Subsequent sulfoxide-lithium exchange, quenching with Ph2PCl and sulfur, then desulfurisation with Raney-Ni provided (R)- and (S)-QUINAP in 54-56% overall yield.