1: (Z)-3-iodo-3-methylpropenoic acid With tetrabutylammomium bromide; palladium diacetate; triphenylphosphine in N,N-dimethyl-formamide T=20°C; 0.166667 h; 2: (tri-n-butylstannyl)-1,2-butadiene in N,N-dimethyl-formamide 4 h;