Answer: (R)-2-chlorobutane and (S)-2-chlorobutane.
- A (R)-2-chlorobutane and (S)-2-chlorobutane
- B (R)-2-chlorobutane and (R)-2-chlorobutane
- C Meso-2,3-dichlorobutane and (R,R)-2,3-dichlorobutane
- D 1-chlorobutane and 2-chlorobutane
Correct answer: A. (R)-2-chlorobutane and (S)-2-chlorobutane
Explanation: Enantiomers are non-superimposable mirror images with opposite configurations at all chiral centres. (R)- and (S)-2-chlorobutane are mirror images with opposite configurations at C-2.
SN2 proceeds in a single step with backside attack and inversion of configuration, while SN1 forms a planar carbocation intermediate first, leading to racemisation.
Concept context
Study carbon-halogen compounds: how they are made, how they react via SN1/SN2 and elimination, their stereochemistry, and their environmental impact.