C2h6 - c2h4 - c2h4br2 - c2h4 - ch3 - ch2cl - ch2=ch2

CH3-CH3 -> CH2=CH2 + H2 (t, kat)
CH2=CH2 + Br2 -> CH2(Br)-CH2(Br)
CH2(Br)-CH2(Br) -> CH=-CH + 2HBr
CH=-CH+H2 -> CH2=CH2(t, kat)
CH2=CH2 + HCl -> CH3-CH2Cl
CH3-CH2Cl + KOH-> CH2=CH2 + KCl + H2O