Question

predict the major product.
rxn i
rxn ii
rxn i rxn ii
a.
+ en
+ en
b.
+ en
+ en
c.
+ en
+ en
d.
+ en
+ en

Explanation:

• For Rxn I:
• The reaction is an electrophilic addition of \(Br_2\) to a cyclohexene - like double bond (in a cyclic alkene). The addition of \(Br_2\) to alkenes follows anti - addition stereochemistry. When \(Br_2\) adds to an alkene, the two \(Br\) atoms add from opposite faces of the double bond.
• For Rxn II:
• When \(Br_2\) reacts with an alkene in the presence of \(H_2O\), the reaction is a halohydrin formation. The \(Br^+\) (from \(Br_2\)) first adds to the double bond to form a cyclic bromonium ion intermediate. Then, \(H_2O\) (as a nucleophile) attacks the more substituted carbon of the bromonium ion (due to the partial positive charge on the carbon atoms of the bromonium ion, and more substituted carbons can better stabilize the partial positive charge). The \(OH\) and \(Br\) add anti - to each other.

Answer:

A. Option Text