C2H5Br ->(Na,t) X1 ->(+Br2, свет) X2 ->(+NaOH,водн. р-р) X3 ->(CuO,t) X4 ->(KMnO4,H,t) X5
2C2H5Br + 2Na (t)= C4H10 + 2NaCl
C4H10 + Br2 (hv)= C4H9Br + HBr
C4H9Br + NaOH = C4H9OH + NaBr
C4H9OH + CuO (t)= C3H7COH + Cu + H2O
C3H7COH + [O] (KMnO4, t)= C3H7COOH