Question

Which of the following has the most acidic proton-
A. $$C{H}_{3}COC{H}_3$$
B.$${\left(C{H}_3\right)}_{2}C=C{H}_2$$
C. $$C{H}_{3}COC{H}_{2}COC{H}_3$$
D. $${\left(C{H}_{3}CO\right)}_{3}CH$$

Answer 1

Hint:The answer can be said as aceto ester and it contains 2 electron withdrawing groups around one compound which is called active methylene group.

Complete answer:
Option C contains 2 electron withdrawing groups around $C{H}_2$ and this $C{H}_2$ group is known as an active methylene group and its hydrogens are acidic in nature.
$$C{H}_{3}COC{H}_{2}COC{H}_3$$(Aceto ester): Pentane-2,4-dione

Hence, Option C is correct.

Additional information:
It is also known as acetylacetone.
It is a beta-diketone which is pentane among which the hydrogens are at 2nd and 4th positions which are replaced by oxo groups. It is a conjugate acid of an acetylacetonate.
These are organic compounds having 2 keto groups which are separated by a single carbon atom.
Pentane-2,4-dione looks like a colourless or yellow coloured liquid which is less dense than water. Vapours are quite heavier than air. It is used as a solvent in paints and varnishes.
It is made by the action of sodium on ethyl acetate and acetone or with the action of anhydrous aluminium chloride on acetyl chloride in the presence of an inert solvent.
Molecular mass is $100.12$ g/mol.
It is colourless or yellowish liquid; when cooled, it gets solidified to lustrous, pearly spangles. The liquid is affected by light, turning brown and forming resins.
Acetylacetone is formed industrially with the help of thermal rearrangement of isopropenyl acetate.
Acetylacetone is an adaptable bifunctional precursor to heterocycles as both are keto groups undergoing condensation. Hydrazine is reacted to form pyrazoles.

Note:
All the following options may look similar but all are different and unique with the structure as well as properties, here due to the $C{H}_2$ group which is known as an active methylene group and the hydrogens are acidic in nature.