Nazarov cyclization is one of the most versatile methods for the synthesis of cyclopentenones from vinyl ketones. For the synthesis a stoichiometric Lewis acid or protic acid promoter is used. The key step of the reaction mechanism involves a cationic 4π-electrocyclic ring closure which forms the cyclopentenone product.

Nazarov cyclization examples catalyzed by cinchona alkaloid derivatives can be found in our free of charge Chiral Catalyst Search Data Base.