âA Friedel-Crafts acylation is an electrophilic aromatic substitution in which the electrophile (E+) is an acylium ion. There are other methods of forming acylium ions, such as treatment of an anhydride with a Lewis acid. The resulting acylium ion can also be attacked by a benzene ring, resulting in acylation of the aromatic ring. Draw the mechanism of the following transformation. For the mechanism, draw the curved arrows as needed. Include lone pairs and charges in your answer. Do not draw out any hydrogen explicitly in your products. Do not use abbreviations such as Me or Ph. Draw step 4 of the mechanism.
