Chiral acid-catalyzed asymmetric nazarov reaction: Nucleophilic construction of a quaternary asymmetric center at the a-position of the keto function

A chiral Lewis acid catalyzed enantioselective Nazarov reaction affording -alkoxy cyclopentenones has been developed. This is the first example for construction of an asymmetric quaternary center by using the monodentate coordinated divinyl ketones via the interrupted Nazarov reaction, which involves a nucleophilic attack of an alcohol on the -position of the keto function.