Tunable Synthesis of 3-Acyl-2-naphthols and 3-Substituted Isocoumarins via Jones Reagent Promoted Cascade Reactions of 2-(4-Hydroxy-but-1-ynyl)benzaldehydes

Novel and efficient synthesis of 3-acyl-2-naphthols and 3-substituted isocoumarins via the tunable cascade reactions of 2-(4-hydroxy-but-1-ynyl)benzaldehydes have been developed. Treatment of 2-(4-hydroxy-but-1-ynyl)benzaldehydes with 0.7 equiv of Jones reagent in CH3CN and subsequent purification through column chromatography on silica gel pre-eluted with Et3N afforded 3-acyl-2-naphthols with high efficiency. When the same substrates were treated with 3 equiv of Jones reagents in acetone, on the other hand, 3-substituted isocoumarins could be obtained in good yields.