Fundamentals of Organic ChemistryChemistryAldehydes and Ketones
Consider the following two structures: (i) (ii) Which of the following statements correctly compares the electrophilic character of the carbonyl carbons in these structures?
Options
- AThe relative electrophilicity depends upon the complete structure of the compound.
- BThe carbonyl carbons of both structures have equal electrophilic character.
- CThe carbonyl carbon of (i) is more electrophilic than that of (ii) .
- DThe carbonyl carbon of (i) is less electrophilic than that of (ii) .
Correct answer
D. The carbonyl carbon of (i) is less electrophilic than that of (ii) .
Step-by-step solution
The electrophilic character of a carbonyl carbon depends on the magnitude of the partial positive charge it carries. In structure (i), the neutral oxygen atom is more electronegative than carbon and withdraws electron density, creating a partial positive charge ( ^+ ) on the carbonyl carbon. In structure (ii), the oxygen atom is protonated and carries a formal positive charge. A positively charged oxygen atom is significantly more electronegative than a neutral oxygen atom. Consequently, it exerts a much stronger e