Помогите решить уравнение
Бутэн1(+br2)->x1(+zn)->x2(+hoh)->x3(-h2o)->x4

CH3-CH2-CH=CH2+Br2 ->CH3-CH2-CHBr-CH2BrCH3-CH2-CHBr-CH2Br+Zn->CH3-CH2-CH=CH2+ZnBr2CH3-CH2-CH=CH2+HOH->CH3-CH2-CHOH-CH3CH3-CH2-CHOH-CH3 ->CH3-CH=CH-CH3+H2O