An efficient route for the syntheses of β-hydroxychalcones containing benzofuran and benzothiophene rings is described. Isoxazolines obtained from oxime-olefin cycloadditions were reduced under pressure to a mixture of products. Isoxazoles obtained from Claisen aroylation of an ester and subsequent acid cyclization, or from isoxazolines via DDQ-mediated dehydrogenation, were subjected to catalytic hydrogenation followed by hydrolysis to afford 1-phenyl-3-(benzofuran-5-yl)-1,3-diketone and 1-phenyl-3-(benzothiophene-5-yl)- 1,3-diketones in very good yields. © 2005 Elsevier Ltd. All rights reserved.
Yadav, P. P., Ahmad, G., & Maurya, R. (2005). An efficient route for commercially viable syntheses of furan- and thiophene-anellated β-hydroxychalcones. Tetrahedron Letters, 46(34), 5621–5624. https://doi.org/10.1016/j.tetlet.2005.06.111