Chapter D, Problem 5PP

Interpretation Introduction

Interpretation:

The conditions for the given reactions to take place are to be identified.

Concept introduction:

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The compounds that have the same molecular formula of atoms but the structure of the compounds are different for the positions of atoms are called isomers.

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In double bond or cyclic compounds, if two same functional groups are present on the same side of the double bond or cyclic compound, the given compound can be labeled as cis.

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If the two functional groups are present on the different sides of the double bond or cyclic compound, the given compound can be labeled as Trans.

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Cis-trans isomerism exists in the compounds in which similar groups are present on the adjacent carbon atoms.

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The electrocyclic reactions are initiated by heat or light and are stereospecific in nature.

According to Woodward-Hoffmann rule:

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The thermal electrocyclic reaction having $4\text{n }\Pi$ electron takes place with conrotatory motion.

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The photochemical electrocyclic reaction having $4\text{n }\Pi$ electron takes place with disrotatory motion.

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The photochemical electrocyclic reaction having $\left(4\text{n+2}\right)\Pi$ electron takes place with conrotatory motion.

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The thermal electrocyclic reaction having $\left(4\text{n+2}\right)\Pi$ electron takes place with disrotatory motion.