Enantioselective bromination/semipinacol rearrangement for the synthesis of beta-bromoketones containing an all-alpha-carbon quaternary center

A bromination/semipinacol rearrangement reaction catalyzed by cinchona alkaloid derivatives was developed. With 5 mol% (DHQD)(2)PYDZ, beta-bromoketones containing an all-alpha-carbon quaternary center, which were synthetically useful but challenging to construct, were obtained in up to 97% yield and 93% ee.