Chapter 18, Problem 78IP

Interpretation Introduction

Interpretation: For the given structure of compound and assigned an IUPAC name are predicted.

Concept Introduction:

• Electrophiles are electron deficient species. In Electrophilic substitution reaction a group or atom in a compound is replaced by electrophile. This kind of reaction occurs predominantly in aromatic compounds. Electrophilic substitution reactions of aromatic compounds are known as aromatic electrophilic substitution reactions.
  • Benzene is an electron rich Aromatic compound. It undergoes aromatic electrophilic substitution reaction. 

• The delocalized nature of pi electrons in benzene attributes a special property to benzene called resonance.

• If the substituent’s on benzene Carbon is Electron withdrawing groups they are known as deactivating groups. They are meta-directing groups because these groups when directly bonded to benzene Carbon decreases the electron density at ortho and para positions and so the incoming electrophile is directed towards meta position.

• ${}^{\text{1}}\text{H}\text{NMR}$: The ${}^{\text{1}}\text{H}\text{NMR}$ spectrum gives information on the different electronic environment of protons. The number of signal (proton types) generated in ${}^{\text{1}}\text{H}\text{NMR}$ are predicted by performing symmetry operations (rotation or reflection symmetry).

• Factors affect the chemical shift values: The electronegative atoms which present nearer to the subjected protons withdraw electron density around the protons inductively makes the protons deshielded and shift the chemical shift value towards downfield.