KCET 2014 Chemistry Solved Paper

An active methylene compound is a compound that has the following general structural formula.Where, E1 and E2 are functional group that withdraws electron by resonance. After the removal of hydrogen from the active methylene groups, the carbanion thus, formed is stabilized by the resonance. Greater the stabilization of the carbanion, greater will be the acidic strength of the active methylene groups.
(I) CH3COCH2COOC2H5So, ketonic groups stabilized more carbanion ion than the ester or carboxylic groups. Therefore, compound having more number of ketonic groups is more acidic active methylene compound.
(II) CH3COCH2COCH3
(III) CH3COOCH2COOCH3Therefore, the decreasing acidic strength of active methylene compounds is (II) > (I) > (III).