An efficient synthesis of C2-symmetric chiral binaphthyl ketone catalysts

An efficient synthesis of C2-symmetric chiral binaphthyl ketones 1a and b, effective catalysts for asymmetric epoxidation, is reported. The key features of this synthesis are Co(salen)-catalyzed macrolactonization of racemic 1,1'-binaphthyl-2,2'-dicarboxylic acid monoglycidyl esters 3a and b and lipase-catalyzed enantioselective acylation of resulting 11-membered cyclic binaphthyl alcohols 4a and b.