1: 1,4-Dihydroxy-2-butyne With 2,2'-azo-bisisobutyronitrile; tri-n-butyl-tin hydride in benzene Heating; 2: tert-butyldimethylsilyl chloride With 1H-imidazole in N,N-dimethyl-formamide T=0°C; 3: With iodine in diethyl ether Title compound not separated from byproducts;