Expeditious photochemical reaction toward the preparation of substituted chroman-4-ones

A facile photochemical preparation of 5-, 6-, and 7-substituted chroman-4-ones from aryl 3-methyl-2-butenoate esters is described. The two-phase base-catalyzed method relies upon two consecutive processes in one-pot reaction through a photo-Fries rearrangement and a based-catalyzed intramolecular oxa-Michael addition to afford the desired products.

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