Question

The Robinson annulation involves two sequential reactions, a Michael addition and an aldol condensation, resulting in the formation of a cyclohexenone derivative. Draw the structure of the two neutral reactants required to form the product shown below.

Answer 1

Concepts and reason

The concept used to solve this question is Robinson annulation.

The two starting materials in Robinson annulation reaction must be an enolate and -unsaturated carbonyl compound.

The ring formation occurs through Michael addition and intramolecular aldol reaction.

Fundamentals

In Robinson annulation, six-membered ring is formed with three new C-C bonds in which two are sigma bonds and one is pi bond.

The example is shown below:

The reterosynthesis is as follows:

The synthesis is as follows:

Ans:

The structures of two neutral reactants are as follows: