SolutionsAcid (Acyl) Halides
1. Handling
Why must acetyl chloride be kept in a tightly closed bottle and in a dry atmosphere? What forms if it is left in air?
It reacts with atmospheric moisture: it is hydrolysed to acetic acid and releases corrosive HCl gas.
2. The most reactive
Why are acyl halides the most reactive derivatives?
The halogen hardly donates electrons to the carbonyl by resonance and withdraws them inductively, so the carbon is very electrophilic. In addition, halide is an excellent leaving group.