SYNTHESIS OF 4(S)-(3,4-DICHLOROPHENYL)-3,4-DIHYDRO-1(2H)-NAPHTHALENONE BY SN2 CUPRATE DISPLACEMENT OF AN ACTIVATED CHIRAL BENZYLIC ALCOHOL

Two routes for the preparation of 4(S)-(3,4-dichlorophenyl)-3,4-dihydro-1(2H)-naphthalenone are reported. The most efficient route generates a chiral benzylic alcohol by catalytic asymmetric oxazaborolidine reduction of a gamma-ketoester that is subsequently activated and displaced in an SN2 manner with a higher order cuprate. Intramolecular Friedel-Crafts cyclization of the resulting t-butylester affords the title compound.