Tandem synthesis of 3-allyl-chromones from alkynones and allylic alcohols under metal-free conditions

A novel and efficient approach to 3-allyl-chromones from alkynones and allylic alcohols via a tandem Michael addition-Claisen rearrangement-O-arylation reaction has been developed. Diversely structural 3-allyl-chromones were afforded in up to 93% yield for 24 examples. This synthetic strategy is regiospecific, highly efficient, environment friendly and metal-free.