The Journal of Organic Chemistry

New syntheses of coumarins

JA Panetta, H Rapoport

Index: Panetta, Jill A.; Rapoport, Henry Journal of Organic Chemistry, 1982 , vol. 47, # 6 p. 946 - 950

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Citation Number: 40

Abstract

New, versatile coumarin syntheses have been developed which are based on the Claisen rearrangement of allylic or propargylic aryl ethers in which the allylic or propargylic a-carbon is further oxygenated. One proceeds by first ester exchange to the aryl dialkyl orthoacrylate which then thermally rearranges. Hydrolytic treatment gives the 0-hydroxydihydrdnnamic acid from which the coumarin is obtained by ring closure and dehydrogenation. In parallel ...