Chapter 17, Problem 46P

Interpretation Introduction

Interpretation:

A suitable reagent for the given organic transformation is to be supplied.

Concept introduction:

Electrophiles are electron deficient species that have positive or partially positive charge. Lewis acids are electrophiles that accept electron pair.

Nucleophiles are electron rich species that have negative or partially negative charge. Lewis bases are nucleophiles that donate electron pair.

Free radical is an atom, molecule, or ion that has an unpaired electron, which makes it highly chemically reactive.

Substitution reaction: A reaction in which one of the hydrogen atoms of a hydrocarbon or a functional group is substituted by any other functional group is called substitution reaction.

Elimination reaction: A reaction in which two substituent groups are detached and a double bond is formed is called elimination reaction.

Addition reaction: It is the reaction in which unsaturated bonds are converted to saturated molecules by the addition of molecules.

The reaction in which there is addition of hydrogen to the double bond is called hydrogenation reaction.

An organic chemical reaction between a conjugated diene and a substituted alkene, generally termed as the dienophile, to form a substitute cyclohexane derivative is known as the Diels-Alder reaction.

The general reaction of Diels-Alder is as:

Diels Alder reaction is between a conjugate diene and a reactant containing double bond (dienophile) to form the product and the product is called adduct.

Diels Alder reactions are highly stereospecific. The configuration, if dienophile is retained in the product and the reaction, is syn addition.

The dienes react with dienophiles in cis forms rather than trans forms.

Endo and exo refers to the orientation of dienophile and its electron withdrawing group, when it reacts with a diene in Diels Alder reaction.

The reaction with orientation of electron withdrawing group of dienophiles under the $\pi$ orbitals of the diene, is Endo.

The reaction with orientation of electron withdrawing group of dienophiles away from the $\pi$ orbitals of the diene, is Exo

Endo is favored in the transition state of Diels Alder reaction because of its lower energy.

If a compound is stable, it has lower energy and if a compound is unstable, it has higher energy.

A carbon-carbon bond formation occurs by aldol addition and aldol condensation reaction.

The reaction in which an enolate ion or an enol reacts with carbonyl compound and forms $\beta -\text{hydroxyaldehyde}$ or $\beta -\text{hydroxyketone}$ is known as an aldol condensation reaction, followed by dehydration, which results in a conjugated enone.

A chemical reaction that is catalyzed by an acid is called acid catalyzed reaction.

A chemical reaction that is catalyzed by an base is called base catalyzed reaction.

Aldol reaction is preferred in basic condition over acidic condition, as after the aldol condensation, acid catalysis promotes the reaction further.

Lithium aluminium hydride is generally used as a reducing agent, especially for the reduction of esters, carboxylic acid.

Desulfurization is a process for the removal of sulfur from a compound or molecule.