5 Pd/C; hydrogen in ethanol T=20°C; 0.5 h; chemoselective reaction;

potassium carbonate in ethanol T=28°C; Addition; Pudovik reaction; 1 h;

1: With sodium azide; copper(l) chloride in DMF (N,N-dimethyl-formamide) T=20°C; 2: diethyl fumarate in DMF (N,N-dimethyl-formamide) T=5°C; 3: diethyl fumarate more than 3 stages;

With  maghemite(γ-Fe2O3) nanoparticle supported 2,2'-bis[3-(triethoxysilyl)propyl]imidazolium substituted diethyl ether bis(tribromide) in  methanol; dichloromethane 6 h;  Reflux;