Осуществите превращения: 
С3Н8-->C3H7CL-->C3H6-->C3H6CL2 
C3H6-->C3H8
 C3H6-->CO2
 C3H6-->C3H7CL

1) C3H8 -> C3H7Cl -> C3H6 -> C3H6Cl2
    1. CH3-CH2-CH3 + Cl2 -> CH3-CH2-CH2Cl + HCl 
    2. CH3-CH2-CH2Cl -> CH3-CH=CH2 + HCl 
    3. CH3-CH=CH2 + Cl2 -> CH3-CHCl-CH2Cl
2) C3H6 -> C3H8
    CH3-CH=CH2 + H2 -> CH3-CH2-CH3
3) C3H6 -> CO2
    2CH3-CH=CH2 + 8O2 -> 6CO2 + 6H2O
4) C3H6 -> C3H7Cl
    CH3-CH=CH2 + HCl -> CH3-CHCl-CH3 - реакция идёт по правилу Марковникова.