Question

PGF2α (Section 4.15) is synthesized in cells using a cyclooxygenase enzyme that catalyzesa multistep radical pathway. Two steps in the pathway are depicted in the accompanying equations.

(a) Draw in curved arrows to illustrate how C is converted to D in Step [1].

(b) Identify Y, the product of Step [2], using the curved arrows that are drawn on compound D.

Short answer

Answer

(a)

Conversion of C to form D

(b)

Formation of compound Y

Step-by-step solution

Step-by-Step SolutionStep 1: Radicals

The chemical species containing an odd number of free electrons are known as radicals.Radicals are highly reactive and may initiate chain reactions in large compounds.

Initiation

The first step of radical reactions is the initiation step. In this step, the homolytic fission of a bond takes place in the presence of heat and light. This step creates radicals.

Propagation

This step gives rise to the chain reaction. In the presence of radical species, bonds of the nearby molecules break off in a homolytic manner to give new radicals.

Chain Termination Reaction

When two radicals combine to form a stable non-radical product, i.e., an adduct, it is called a chain termination reaction.

Radical reaction in the given compound

(a) In the presence of an oxygen radical, the nearby double bond undergoes homolytic fission. This gives a product D from C.

Conversion of C to form D

(b) Following the curved arrows, the new product Y formed is shown hereunder.

Formation of compound Y