Brønsted-Acid-Catalyzed Synthesis of 3‑Alkoxy and 3‑Sulfamido Indanones via a Tandem Cyclization

Brønsted-acid-catalyzed allylic
substitution reactions of the in situ generated 3-hydroxy indanones
with alcohols and sulfamides were investigated, which provided a facile
route for the synthesis of a large variety of 3-alkoxy and 3-sulfamido
indanones. The key intermediates, 3-hydroxy indanones, were obtained
through the intramolecular Meyer–Schuster rearrangement of o-propargyl alcohol benzaldehydes. The resulting 3-benzyloxy
indanone could be selectively modified by allylic sulfonamidation
and reduction reactions.