What is the major product of each of the following reactions?
a.

Verified step by step guidance

Step 1: Analyze the structure of the reactant. The molecule is a substituted cyclohexene with a double bond and two methyl groups attached to the ring. The reaction involves HBr, which suggests an electrophilic addition mechanism.

Step 2: Identify the mechanism of the reaction. HBr adds to alkenes via electrophilic addition. The proton (H⁺) from HBr will first attack the double bond, forming a carbocation intermediate.

Step 3: Determine the regioselectivity of the reaction. According to Markovnikov's rule, the proton will add to the carbon of the double bond that has more hydrogens, resulting in the formation of the more stable carbocation intermediate.

Step 4: Consider carbocation stability. The carbocation formed will be tertiary due to the presence of the two methyl groups, which stabilize the carbocation through hyperconjugation and inductive effects.

Step 5: Complete the reaction. The bromide ion (Br⁻) will attack the carbocation, leading to the formation of the major product, which is a brominated cyclohexane derivative at the most substituted carbon.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Video duration:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Hydrohalogenation

Hydrohalogenation is an electrophilic addition reaction where a hydrogen halide (like HBr) adds across a double bond in an alkene or alkene-like structure. The reaction typically follows Markovnikov's rule, where the hydrogen atom attaches to the carbon with more hydrogen substituents, leading to the formation of a more stable carbocation intermediate.

Carbocation Stability

Carbocation stability is a key concept in organic chemistry, as the stability of the carbocation intermediate influences the outcome of reactions. Carbocations are classified as primary, secondary, or tertiary based on the number of alkyl groups attached to the positively charged carbon. Tertiary carbocations are the most stable due to hyperconjugation and inductive effects from surrounding alkyl groups.

Markovnikov's Rule

Markovnikov's rule states that in the addition of HX to an alkene, the hydrogen atom will bond to the carbon atom that has the greater number of hydrogen atoms already attached. This rule helps predict the major product of hydrohalogenation reactions, guiding chemists in understanding the regioselectivity of the reaction and the formation of more stable products.

Recommended video:

Guided course