AlCl3, aluminium chloride in dichloromethane T=20°C; Friedel-Crafts Acylation; 3 h;

copper(l) iodide; lithium chloride in tetrahydrofuran T=20°C; 2 h; Inert atmosphere;

1: toluene-4-sulfonic acid / toluene / 12 h / Reflux 2: N-bromosuccinmide / N,N-dimethyl-formamide / 12 h / 50 °C / Reflux 3: 2,3-dihydroxybutanedioic acid / water; N,N-dimethyl-formamide / 4 h / 60 °C View Scheme