3-Substituted lawsones were synthesized via a chemoselective HMR-enabled ring expansion of indanone substrates. The transformation proceeds through epoxidation, quinone methide-type intermediate formation, ring expansion, and benzylic sp3 C–H oxidation. This operationally simple protocol provides direct access to 3-aryl- and 3-heteroaryl lawsones in moderate to good yields from readily available precursors capable of generating ortho/para-quinone methide-type intermediates. The method avoids transition-metal catalysis and prefunctionalization, offering a streamlined approach to highly functionalized 3-substituted lawsones.
Banyangala et al. (Tue,) studied this question.