The decomposition of diazo ester 2b with chiral RhII catalysts proceeded via intramolecular aromatic carbenoid insertion to the racemic pyrrole derivative 5b in 72% yield. In contrast, the benzoylated precursor 16 afforded no ketorolac 1b when exposed to RhII. Methyl 2‐diazo‐4‐phenylbutyrate (19), in turn, reacted, by 1,2‐hydrogen migration rather than by aromatic substitution, to 20.