Question

6. Circle the aromatic compounds from the list below. (5 points)

7. Rank the compounds below in order of reactivity to Electrophilic Aromatic Substitution. Rank the most reactive compound as compound 1 and the least reactive compound as compound 5. (5 points)

6. Circle the aromatic compounds from the list below. (5 points) OH :O: H 7. Rank the compounds below in order of reactivity to Electrophilic Aromatic Substitution. Rank the most reactive compound as compound 1 and the least reactive compound as compound 5. (5 points) NO2 oddao SO3H

Answer 1

0 The alee the molecule must following conditions for necessary aromacity Đ The be cyclic 4) The molecule must be planer. c) Every ring must be conjugated have an available 'p' orbital. i) de According to Hucket's rule aromasty, the should have (4m +2/ nelectrons. atom in the must molecule Not y planer. sps hybridised. (tetrahedral carbon). Hence non aromatic % Also ring not conjugated or the in the g planer cone pair of elechon negative charge is dispersed sing 8 electrons in conjugation. : 4m (n=2) T electrons. electrons OY Hence anti arro matic co ☺ planer the atoms are with each other. in conjugation j) (4m +2) n electron (M1). (6n e-) N Aromatic Aromatic

H involued in have . Plauer ring % Au atoms orbital hence conjugation. 8 7 elections ( 4 from double bondo 2 from oxygen 2 from Nit vitragend one nitrogen)} 4m (n=2) Anti aromatic. OH OH ☺ planer y fally conjugated sing. br dectrons 4n+2 (na) W Aromatic there arte electron species where most susceptible to electrophilia it stabilises because 7 In releasing groups substitution reaction ear bocation - ike intermediate electrophile 95 electron react reading with a election density the Also an it will > loving ring with maximan .

-OH aree electron releasi easing groups (tr) (FI) -etta groups groups groups electron -NG an electron with drawing group -I - CHO 12 .17 - S 03 4 • -OH → +R effect Cactivates the ring) etty hyper conjugative til effect) (activates ) , 103H (-It-R) (decreases electron density of ring) etivating groups . NO2) to I deactiv sos increased to OH os (election density in the ring (tIf +R) a great extent ) groups (substituents). Most Reactive. (elechon density greatly decreased from ring -Cho 5 by -R of of Noze groups). least Reactive