1: 1.) butyl-lithium, di-isopropylamine, dimethyl sulphide, copper(I) bromide, 2.) aq. copper (II) acetate / 1.) THF, hexane, 0 deg C, 30 min, 2.) THF, 2 h 2: trifluoroacetic anhydride, pyridine / CH2Cl2 / 1 h View Scheme

1: 1.) aq. sodium hydroxide / 1.) 20 deg C, 2 d, 2.) acetone, reflux, 6 h 2: trifluoroacetic anhydride, pyridine / CH2Cl2 / 1 h View Scheme

1: 1.) trifluoroacetic acid, 2.) aq. sodium hydroxide / 1.) benzene, 5 min, 2.) diethyl ether, 2 min 2: 1.) aq. sodium hydroxide / 1.) 20 deg C, 2 d, 2.) acetone, reflux, 6 h 3: trifluoroacetic anhydride, pyridine / CH2Cl2 / 1 h View Scheme

pyridine; trifluoroacetic anhydride in dichloromethane 1 h; Title compound not separated from byproducts;