Why does the friedel crafts acylation of anisole favor the para-methoxyacetophenone?

Answer 1

Anisole has a methoxyl group that participates in activating the benzene ring during acylation. When the benzene ring breaks its bond in order to attach an acetone functional group, it is destablized and therefore energy unfavorable. However, other functional groups like alkoxides (-OR) animo (-NR2), thio groups (-SR) all have lone electrons AND single bonds, which can form into double bonds--donating those electrons to the benzene ring and stabilizing its positive charge. The attachment will always para to the activating group due to steric effects, followed by ortho position due to specific locations that the positive charge can exist (when the methoxyl group adds its electrons).

Answer 2

The Friedel-Crafts acylation of anisole favors the para position due to steric hindrance. The methoxy group on anisole directs the incoming acyl group to the para position through resonance effects, creating a more stable product. Additionally, the para position is less sterically hindered compared to the ortho position, making it easier for the acylation reaction to occur at that position.