Which is the correct order of decreasing acidity of the hydrogens on the carbon marked by the pKa data in these compounds?

A $CH X_{3} COCH X_{2} COCH X_{3} > CH X_{3} COCH X_{2} COOC X_{2} H X_{5} > CH X_{3} COCH X_{3} > C X_{2} H X_{5} OOC - CH X_{2} - COOC X_{2} H X_{5}$
B $CH X_{3} COCH X_{2} COCH X_{3} > CH X_{3} COCH X_{2} COOC X_{2} H X_{5} > C X_{2} H X_{5} OOC - CH X_{2} - COOC X_{2} H X_{5} > CH X_{3} COCH X_{3}$
C $CH X_{3} COCH X_{2} COCH X_{3} > C X_{2} H X_{5} OOC - CH X_{2} - COOC X_{2} H X_{5} > CH X_{3} COCH X_{2} COOC X_{2} H X_{5} > CH X_{3} COCH X_{3}$
D $CH X_{3} COCH X_{2} COOC X_{2} H X_{5} > CH X_{3} COCH X_{2} COCH X_{3} > C X_{2} H X_{5} OOC - CH X_{2} - COOC X_{2} H X_{5} > CH X_{3} COCH X_{3}$

Answer: B

pKa values: pentane-2,4-dione 9.0, ethyl 3-oxobutanoate 10.7, diethyl propanedioate 13, propanone 19.3. A ketone carbonyl stabilises the carbanion more than an ester carbonyl, and two acceptor groups are better than one, giving the stated order.

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Which is the correct order of decreasing acidity of the hydrogens on the carbon marked by the pKa data in these compounds?

Answer: B

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