in methanol Ambient temperature;

triethylamine in acetonitrile 5 h; Irradiation;

1: 4-dimethylamino-benzaldehyde With potassium tert-butylate; (methoxymethyl)-triphenylphosphonium chloride in tetrahydrofuran T=0 - 20°C; 12 h; 2: formic acid With hydrogenchloride in dichloromethane; water 12 h; Reflux;

Acid hydrolysis;