Abstract: Citronellal oxime(2) was prepared from the reaction of citronellal and hydroxylamine hydrochloride under the alkaline condition provided by sodium carbonate. And then, four kinds of citronellal oxime alkyl ethers, respectively, citronellal oxime ethyl ether(3a), citronellal oxime n-propyl ether(3b), citronellal oxime n-butyl ether(3c), citronellal oxime n-penta ether(3d), were prepared from the halogenated reaction of citronellal oxime with five alkyl bromides, sodium hydroxide and the phase transfer catalyst tetrabutyl bromide ammonium. Identification and structural analysis were done by using FT-IR,NMR(¹H NMR, ¹³C NMR) and GC-MS methods. And the antifungal activities of all compounds against eleven plant pathogenic fungi were studied by using the mycelial growth rate method. The structural analysis results showed that the method could synthesize 5 target compounds and the antifungal activity test showed that at the mass concentration of 500 mg/L, the five compounds had certain antifungal activity against the eleven tested plant pathogenic fungi. Among these inhibitory rate dates, the inhibition rate of compound 2 on Rhizoctonia solani reached 100%,equal to that of chlorothalonil,the inhibition rate on Sclerotinia sclerotiorum,Phytophthora capsici,Botryis phariadothide,Alternaria kikuchiana and Ceratosphaeria phyllostachydis reached 100%, the inhibition rates on Glomerella cingulata and Fusarium proliferatum also reached high inhibition rates(≥ 95%),which were much higher than the inhibition abilities of chlorothalonil against these pathogens; the inhibition rate of 3a on Lettuce sclerotinia reached 100%, the inhibition rate of 3b on Colletorichum gloeosporioides reached 100%, the inhibition rate of 3c on Ceratosphaeria phyllostachydis reached 87.7% and the inhibition rate of 3d on Lettuce sclerotinia reached 96.2%,these all were higher than the inhibition rates of chlorothalonil on these pathogenic fungi at the same mass concentration.

Key words: citronellal, citronellal oxime, citronellal oxime ether, structural analysis, antifungal activity