1: With phosphorus pentachloride T=0 - 75°C; 1.75 h; 2: With N,N-dimethyl-formamide T=20°C; 72 h; 3: With sodium hydroxide in water T=0°C; pH=8;

1: 2-benzyloxyacetaldehyde diethyl acetal With phosphorus pentachloride T=0 - 75°C; 2.08333 h; 2: N,N-dimethyl-formamide T=20°C; 72 h; 3: With sodium hydroxide in water pH=>= 8;

sodium hydride in 1-methyl-pyrrolidin-2-one T=0 - 80°C; 1 h;