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

The first successful example of a catalytic enantioselective intramolecular Tishchenko reaction of a meso -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 ( S )-cedarmycins A and B.