Question

Question: Label each product in the following reaction as a 1,2-product or 1,4-product, and decide which is the kinetic product and which is the thermodynamic product.

Short answer

Answer

The 1,2-addition product is the kinetic product, and the 1,4- product, which has the more substituted double bond, is the thermodynamic product.

Step-by-step solution

Kinetic product

The 1,2-addition product is formed faster because it dominates at low temperatures. The product that is formed faster is called the kinetic product.

The kinetic product formation rate is faster compared to the thermodynamic product because it has low activation energy.

Thermodynamic product

The 1,4-addition product must be more stable because it predominates at equilibrium. The product that predominates at equilibrium is called the thermodynamic product.

The thermodynamic product rate is slow due to its high activation energy.

Reaction mechanism

The mechanism of the product formation is as shown below:

Kinetic and thermodynamic products