potassium carbonate in N,N-dimethyl-formamide T=20°C; 3 h;

1: 4-bromo-phenol With tert.-butyl lithium; isopropylmagnesium chloride in tetrahydrofuran; pentane T=-78°C; 0.5 h; 2: bromoacetic acid tert-butyl ester With sulfur T=-78 - 20°C;