15 . B
The nomenclature in this question is well above what one needs to be able to draw on the MCAT;
however, we can discern that we are forming a ketone and an aldehyde from a single molecule.
The hallmark of a reverse aldol reaction is the breakage of a carbon–carbon bond, forming two
aldehydes, two ketones, or one of each. In an aldol condensation, choice (A), we would expect to
form a single product by combining two aldehydes, two ketones, or one of each. A dehydration
reaction, choice (C), should release a water molecule, rather than breaking apart a large organic
molecule into two smaller molecules. A nucleophilic attack, choice (D), should feature the
formation of a bond between a nucleophile and an electrophile; again, we would not expect to
break apart a large organic molecule into two smaller molecules. Note that simply noting how
many reactants and products are present in the reaction is sufficient to determine the answer.
