1: cis,cis-9,12-octadecadienoic acid With O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate; triethylamine in ethyl acetate T=20°C; 1 h; 2: isopropylamine in ethyl acetate T=20°C; 12 h;