Enantioselective Intramolecular Friedel-Crafts-Type α-Arylation of Aldehydes

Enantioselective organo-SOMO catalysis has, in the last two years, been the subject of considerable development and exploration. A number of new and unique transformations have been reported, such as alpha-allylation, alpha-oxyamination, alpha-enolation, and alpha-vinylation of aldehydes. Herein, we report a modification of this activation mode that involves the intramolecular Friedel-Crafts-type alpha-arylation of aldehydes carrying etectron-donating groups on their aromatic nucleus and its application to the total synthesis of demethyl calamenene, a potent cytotoxic agent against human adenocarcinoma A 549.