Question

For each pair of esters below specify which undergoes basic hydrolysis faster. CO2CH3 _C02CH3 Ester a: H3C0 Ester b: Na B: NEC- Ester a: CH3CO2CH(CH3)2 Ester b: CH3CO2C(CH3)3 -

Answer 1

12 lo, CH3 yeezeH3 CH3° + (-) Besie Hydrolysis of Ester : - Mechanism :- Netco -I effec (6) e -OCH3 Copy copy ra H 3 etó Here Nu OHO wat delta attack to the electrophike Carbon centre. More the centre will be electrophilic the reaction rate will Faster . Now, for ester (a) OCH3 at para position has ti effect and in ester (6) en at para position has -I effect. So, electrophile character of carbonyl carbon increases in ester b. so, Basic Hydrolysis of ester b will faster. 2) CH-f-o - cu cu , CH - - - - - Feltz In ester (a) there are 2 Me group connected to eat carbon centre . But in ester (le) 3 me groups connected to e centre. eta group has to effect. It increases electron density in the adjacent carbonyl Carbon with so, Basic Hydrolysis of Ester CamScanwill be faster.