Question

How will you carry out the following conversions?

1-chloropropane to 2-chloropropane

Answer 1

To convert 1-chloropropane to 2-chloropropane, the transformation is carried out in two main steps:

1. Convert 1-chloropropane to propene by heating with alcoholic KOH (elimination reaction). This removes HCl and forms a double bond:
   \[\ce{\underset{1-chloropropane}{CH3CH2CH2Cl}->[alc{.} KOH][]\underset{propene}{CH3CH=CH2}}\]
2. Add HCl to propene in the presence of peroxide-free conditions (electrophilic addition). According to Markovnikov’s rule, the Cl attaches to the more substituted carbon:
   \[\ce{\underset{propene}{CH3CH=CH2} + HCl->\underset{2-chloropropane}{CH3CH(Cl)CH3}}\]