Recently, we disclosed the first examples of an enantioselective variant of this process (Scheme 1B). 9 The methodology exploits the aforementioned relative acidity of homophthalic anhydrides such as 6 in conjunction with an ad hoc-designed bifunctional organocatalyst, which we suggested was capable of promoting both enol formation and face-selective addition to the aldehyde electrophile. The process generates bicyclic lactone products such as 8 which ...
