Ester given nucleophilic additionreactionfollowed by eliminationreaction withcarbon nucleophile . Whencarbon nucleophileis of anesterthenthe reactionis knowas Claisencondensationreaction. This reactions is alsocarrieout betweenester and aketone. Asuccessful Claisencondensationrequires an ester withtwo alpha- hydrogensand aan equivalentamountof base ratherthan acatayticamount of base . Consider the givereactionCH_(3) - COOC_(2)H_(5) underset(C_(2)H_(5)OH)overset(C_(2)H_(3)ONa) to "enolate ion" underset("Claisen condensation")overset("ester(X)")to ProductFor theabovereactionthe mostreactiveesteris :

Ester given nucleophilic additionreactionfollowed by eliminationreacti

1.	Ester given nucleophilic additionreactionfollowed by eliminationreaction withcarbon nucleophile . Whencarbon nucleophileis of anesterthenthe reactionis knowas Claisencondensationreaction. This reactions is alsocarrieout betweenester and aketone. Asuccessful Claisencondensationrequires an ester withtwo alpha- hydrogensand aan equivalentamountof base ratherthan acatayticamount of base . Consider the givereactionCH_(3) - COOC_(2)H_(5) underset(C_(2)H_(5)OH)overset(C_(2)H_(3)ONa) to "enolate ion" underset("Claisen condensation")overset("ester(X)")to ProductFor theabovereactionthe mostreactiveesteris :
Answer» `C_(6)H_(5)CO OC_(2)H_(5)` `C_(2)H_(5)O-overset(O)overset(\|\|)(C) -overset(O)overset(\|\|)(C) = OC_(2)H_(5)` `HCO OC_(2)H_(5)` `C_(2)H_(5) O- overset(O)overset(\|\|)(C) - OC_(2)H_(5)` ANSWER :A