()-|||-_(6)(H)_(5)CH=!=!= C(H)_(2)xrightarrow (HBr) () Mg (1) C O2 ( ()-|||-A C6H5CH2C H2Br-|||-B C6H5CHBrCH3-|||-C ._(6)(H)_(5)CH(C(H)_(3))COOH-|||-._(6)(H)_(5)C(H)_(2)C(H)_(2)COOH