4 chromanone derivative 4 Michael addition 4 catalysis 4 cyclohexane 4 ester derivative 4 photochemistry 4 reaction analysis 4 3 methyl 2 butenoate ester derivative 2 Article 2 Aryl esters 2 Chroman-4-ones 2 Two-phase reaction 2 article 2 chemical reaction 2 cyclization 2 heterocyclic compound 2 natural product 2 one pot synthesis 2 oxa-Michael addition 2 photo Fries rearrangement 2 photo-Fries rearrangement 2 potassium hydroxide 2 quantum yield 2 reaction time 2 room temperature 2 synthesis 2 unclassified drug 2