Choose the correct reactivity order among following heterocyclic compounds (towards electrophilic substitution reaction)I. Pyrrole; II. Furan; III. Thiopene; IV. Benzenea)IIIIIIIVb)IIIIIIIVc)IIIIVIIId)none of theseCorrect answer is option 'A'. Can you explain this answer?

Question

Choose the correct reactivity order among following heterocyclic compounds (towards electrophilic substitution reaction)I. Pyrrole; II. Furan; III. Thiopene; IV. Benzenea)I>II>III>IVb)II>I>III>IVc)I>II>IV>IIId)none of theseCorrect answer is option 'A'. Can you explain this answer?

Answer

. Pyrrole > II. Furan > III. Thiophene > IV. Benzene

Answer

Heterocycles have heteroatoms which can donate lone pairs and enhance the electron richness of the ring.So benzene is least reactive.
Since oxygen has higher electronegativity than nitrogen, it has lesser tendency to donate its lone pair.Hence pyrrole is more reactive than furan.
Though S has lesser electronegativity than N, the overlap occurs between 3p orbital of S and 2 p orbitals of C in thiophene implies less effective overlap. Hence the order as in option A.

Similar Chemistry Doubts

Among the following compounds, how many compound(s) are more reactive towards electrophilic substitution reaction than compound ‘A’? Correct answer is '2'. Can you explain this answer?

Which of the following is rate determining step in electrophilic substitution reaction?

The reaction of sodium ethoxide with ethyl iodide to form diethyl ether is termed

How many of the following heterocyclic compound(s)is/are aromatic? Correct answer is '5'. Can you explain this answer?

A compound with molecular formula C4H4O has all the four carbon atoms and the oxygen atom in the ring. It also has two double bonds. The compound is: Correct answer is 'heterocyclic and aromatic'. Can you explain this answer?

Top Courses for Chemistry

Suggested Free Tests

Related Content

Schools

Competitive Examinations

Quick Access Links

Technical Exams