The synthesis of 8‐allyl‐2‐styrylchromones by the modified baker‐venkataraman transformation

Substituted‐2‐hydroxy‐3‐allylacetophenones 2 react with cinnamoyl chlorides 3 in potassium carbonate‐acetone to give good yields of polyfunctional 1‐(2‐hydroxy‐3‐allylaryl)‐5‐aryl‐4‐pentene‐1,3‐diones 4 which exist in their enol forms 5 . These on acid catalysed cyclodehydration gave 70–80% yields of substituted 8‐allyl‐2‐styrylchromones 6 .