Syntheses and biological activities of pyranyl-substituted cinnamates

Twenty-two kinds of pyranyl-substituted cinnamates were synthesized by the reaction of 4-hydroxy-6-(2-phenylethyl)-2H-pyran-2-one or 4-hydroxy-6-methyl-2H-pyran-2-one (HMP) with a variety of substituted cinnamic acids, and their antifungal and plant growth inhibitory activities were investigated. Among the compounds prepared, 6-methyl-2-oxo-2H-pyran-4-yl 3-(4-isopropylphenyl)propenoate (H5) showed the strongest antifungal activity against Rhizoctonia solani and Sclerotium dellfinii, and 6-methyl-2-oxo-2H-pyran-4-yl 3-(2-methylphenyl)propenoate (H2) had the highest plant growth inhibitory activity toward Brassica rapa.