Question

5) Which sequence correct electrophilic aromatic substitution reaction? tly ranks the following aromatic rings in order of increasing rate of reactivity in an CH Ha OCH A) 1 <2 <3 B) 2 <3 < 1 C) 3 <1 <2 D)2 <1<3 6) Show how you would perform the following synthesis A)1.03 2. (CH3)2S B) KMn04, cold, basic C) Os04 D) 1. mCPBA 2. potassium dichromate

5) Which sequence correctly ranks the following aromatic rings in order of increasing rate of reactivity in an electrophilic aromatic substitution reaction?

6) Show how you would perform the following synthesis.

9) Which sequence ranks the following carbonyl compounds in order of increasing rate (slowest to fastest) of nucleophilic addition?

10) What would be the product for the following reaction?

Answer 1

5) Electrophilic aromatic substitution: In this type of reactions, benzene ring behave as a nucleophile. Functional group which is attached with benzene ring will responsible for the position of incoming group and the nature of attached functional group also affects the reaction rate. Ifelectron donating group (EDG) attached with the aromatic ring it increases the reactivity of aromatic ring by pushing electron density towards the ring. These electron donating group also called activating groups. If electron withdrawing group (EWG) attached with the aromatic ring it decreases the reactivity of aromatic ring by pulling the electron density from the ring and aromatic ring will becomes deactivated therefore these groups are called deactivating groups.

+R 0: CH3 CH CH; CH CH Ester group (-OCOCH3) is a -IE and +RE group and directs the incoming electrophile towards ortho, para positions. It will weakly activates the benzene ring. Therefore, benzene ring becomes more reactive toward electrophilic aromatic substitution reaction. Methyl (-CH s a IE group that directs the incoming electrophile towards ortho, para positions. It shows hyperconjugation It will weakly activates the benzene ning

Methoxy group (-OCH) is a IE and +RE group and directs the incoming electrophile towards ortho, para positions. It is more effective due to resonance. It will strongly activates the benzene ring. Therefore, benzene ring becomes more reactive toward electrophilic aromatic substitution reaction. Methoxy group strongly activates the benzene ring than ester. And ester more strongly activates the benzene ring than methyl. Thus, the option (D) is correct. D)2<1<3 6) The complete synthesis is given as shown below 2. (CH32S The di-carbonyl compound can be easily synthesized from the given alkene by an ozonolysis reaction followed by reduction of the ozonide with dimethyl sulfide (CH3)2S Thus, the option (A) is correct.