1: With zirconocene dichloride; ethylaluminum dichloride; magnesium in tetrahydrofuran 6 h; Inert atmosphere; 2: With sulfur in benzene T=80°C; 6 h; Inert atmosphere;

sulfur; zirconocene dichloride 1.) RT, 6-8 h, 2.) benzene, 80 deg C, 6 h; Multistep reaction;

sodium periodate in water T=0°C;