The first example of cine-substitution for 3-nitrocoumarins. Effective approach to the synthesis of 2H-chromen-2-ones containing 3-hydroxypyran-4-one fragment

Abstract

For the first time we have demonstrated the feasibility of cine-substitution for 3-nitrocoumarins. Based on this process a novel efficient one-step protocol for the preparation of substituted 2H-chromen-2-ones bearing 3-hydroxypyran-4-one moiety has been developed. The presented method includes base-catalyzed reaction of allomaltol derivatives with various 3-nitrocoumarins. The reaction proceeds under mild conditions and products are readily available using a simple purification procedure. The structure of one of the 2H-chromen-2-one derivatives has been determined by X-ray diffraction.