Highly Enantioselective Hetero‐Diels–Alder Reaction of 1,3‐Bis(silyloxy)‐1,3‐dienes with Aldehydes Catalyzed by Chiral Disulfonimide

Bulking up with F: The title reaction proceeds using 1 mol % of the new perfluoroisopropyl chiral disulfonimide catalyst 1 to deliver several 2,6-disubstituted and 2,5,6-trisubstituted dihydropyrones in good yields and with excellent enantiomeric ratios. The utility of this methodology is illustrated with the first enantioselective synthesis of a potent aromatase inhibitor.