Reaction of 3-(3-Arylacryloyl)-2H-chromen-2-ones with Methyl 1-Bromocyclopentanecarboxylate and Zinc.

Reformatsky reagent obtained from methyl 1-bromocyclopentanecarboxylate and zinc selectively added to the carbon–carbon double bond of the heterocyclic fragment of 3-(3-arylacryloyl)-2H-chromen-2-ones to give the corresponding addition products after hydrolysis of the reaction mixture. According to the X-ray diffraction data, the products exist in the enol form. Despite the use of excess Reformatsky reagent, elevated temperature, and prolonged reaction time, neither addition to the acryloyl fragment nor intramolecular cycliza-tion of the addition products was observed. [ABSTRACT FROM AUTHOR]