triethylamine in benzene T=20°C;

1: o-methoxybenzaldehyde oxime With pyridine; N-chloro-succinimide in tetrahydrofuran T=20 - 60°C; 1 h; Inert atmosphere; 2: propargyl alcohol With triethylamine in tetrahydrofuran T=50°C; 3 h; Inert atmosphere;

1.1: NH2OH*HCl; Na2CO3 / ethanol; H2O / 1 h / 60 °C 2.1: N-chlorosuccinimide; pyridine / tetrahydrofuran / 0.5 h / 60 °C 2.2: triethylamine / tetrahydrofuran / 2 h / 50 °C View Scheme

1: N-chloro-succinimide / N,N-dimethyl-formamide / 0.5 h / 20 °C / ultrasonic irradiation 2: triethylamine / N,N-dimethyl-formamide / 0 °C / ultrasound irradiation View Scheme

silica gel; pyridinium chlorochromate in dichloromethane T=20°C; 6 h;