Consider the following reaction The number of stereoisomer(s) formed during this reaction will be
Show Hint
Always check if the product can have a meso form. In this case, since the groups at C1 (Cl, Me) and C2 (H, Me) are different, no internal plane of symmetry exists, so there are no meso compounds.
{Step 1: Understanding the Concept:}
Electrophilic addition of HCl to an alkene proceeds via a carbocation intermediate, following Markovnikov's rule.
{Step 2: Detailed Explanation:}
1. Mechanism: Protonation of the double bond gives a stable tertiary carbocation at one of the ring carbons.
2. Product: Chloride ion then attacks the carbocation, yielding 1-chloro-1,2-dimethylcyclopentane.
3. Stereocenters: The product has two chiral carbons: C1 (bonded to Cl, Me, C2, C5) and C2 (bonded to H, Me, C1, C3).
4. Counting Isomers: With 2 chiral centers and no plane of symmetry (due to Cl vs H at the two sites), the total number of stereoisomers is \(2^n = 2^2 = 4\). These comprise two pairs of enantiomers (RR/SS and RS/SR).
{Step 3: Final Answer:}
The number of stereoisomers formed is 4.
