Catalytic enantioselective intramolecular Tishchenko reaction of -dialdehyde: synthesis of ()-cedarmycins.

The first successful example of a catalytic enantioselective intramolecular Tishchenko reaction of a -dialdehyde in the presence of a chiral iridium complex is described. Chiral lactones were obtained in good yields with up to 91% ee. The obtained enantioenriched lactones were utilized for the first synthesis of ()-cedarmycins A and B.