Synthesis and Herbicidal Activity of 12--1,15-pentadecanolides

12-(Substituted phenoxy-iso-butyroxyimino)-1,15-pentadecanolides were synthesized through the reaction of 12-(hydroxyimino)-1,15-pentadecanolide with substituted phenoxy-iso-butyl acid. All novel compounds were confirmed by 1H NMR, 13C NMR and elemental analysis. Preliminary bioassay indicated that all synthesized compounds showed the herbicidal activity of some compounds to Amaranthus tricolor L., the EC50 value of compound Ⅲa~Ⅲd were 34.570,46.492,55.385,50.114 mg/L,respectively, were higher than that of 2,4-D(117.325 mg/L), but lower than that of tribenuron-methyl(22.381 mg/L).