1: With triethylamine in hexane T=20°C; Inert atmosphere; 2: With toluene-4-sulfonic acid in hexane T=70°C; Inert atmosphere; regioselective reaction;

1: With sodium ethanolate in ethanol T=20°C; 20 h; 2: With hydroxylamine hydrochloride; acetic acid in ethanol; water 20 h; 3: With toluene-4-sulfonic acid in ethanol 2 h; Reflux;