With maleic acid as the raw material,6-methyl-4-hydroxy-2-pyrone,6-methyl-4-alkoxy-2-pyrone and 6-methyl-4-hydroxy-3-acyl-2-pyrone derivatives were obtained via
Resistance of 17 major rice cultivars in Hangzhou region of China against southern rice black-streaked dwarf virus was tested in the paper. The results showed t