• Can be used to introduce a carboxyl group into an aromatic ring by Friedel-Crafts acylation, followed by cleavage of the resulting ketone with KO-t-Bu. With this aryl group, cleavage occurs in only one of the two possible senses. For an example, (ferrocenecarboxylic acid), see: Org. Synth. Coll., 6, 625 (1988).
Corrosive (C)