Cl                                                                                                             =OCH3-CH2-CH-Cl --(2KOH, H20)-- больше X1 --(K2Cr2O7, H2SO4)-- больше CH3-CH2-C-OH --(Cl2, P кр...

                    Cl                                                                                                             =O CH3-CH2-CH-Cl --(2KOH, H20)--> X1 --(K2Cr2O7, H2SO4)-->CH3-CH2-C-OH --(Cl2, P красный)--> X2 --(NaHCO3)--> X3 --(CH3-CH2-Br)--> X4