Design,synthesisandfungicidalactivityofnovelisoxazolinesfromeugenol

In order to discover new fungicidal lead compounds, 35 isoxazolines have been synthesised( D1-D32 , E1-E3 ), among which 34 isoxazolines are novel compounds. In this synthesis, 32 chlorinated oximes were first synthesized from commercially available and inexpensive aromatic aldehydes. The following 1, 3-dipolar cycloaddition with the natural product eugenol and late-stage functionalization furnished the target compounds.The synthesized compounds were characterized by LC-ESI-MS, ¹H NMR and elemental analyses. Preliminary bioactivity tests showed that the synthesized isoxazolines demonstrated good activity against Sclerotinia sclerotiorum, Rhizoctonia solani, Alternaria solani and Phytophthora capsici. Compound D26 has the best inhitory effect against S. sclerotiorum with the EC₅₀ value of 14.3 mg/L, which can be used as a novel lead compound for the discovery of new antifungal leads.