Synthesis of Substituted Quinolizidines via a Gold‐Catalyzed Double Cyclization Cascade

Abstract A novel synthesis of quinolizidines by a cationic gold‐catalyzed double cyclization cascade has been developed. The reaction was initiated by the gold‐catalyzed 6‐ exo ‐ dig cyclization of ynamides, which was followed by a second cyclization of an enamide intermediate to provide the corresponding quinolizidine derivatives. The utility of this reaction was demonstrated by application to the synthesis of multi‐substituted quinolizidines and by the total synthesis of a quinolizidine alkaloid, (±)‐lupinine. magnified image