Synthesis and X-ray study of Hexahydro- and tetrahydrophospholo-[2,3-d]isoxazoles, a new class of heterocycles of potential fungicidal activity

Article abstract of DOI:10.1002/jhet.5570330416

Hexahydro-, 5b-I and 6a,f,I and tetrahydrophospholo[2,3-d]isoxazoles 8, 9 and 10 were synthesized by 1,3-dipolar cycloaddition of nitrones 3b-I and benzonitrile oxide (4) to 2,3-dihydro-1-phenyl-1H-phosphole 1-oxide (1) and 2,3-dihydro-1-ethoxy-1H-phosphole 1-oxide (2). The structural assignment to the compounds was confirmed by an X-ray study of two compounds of the series Sa and 5m. The compounds show a good activity as fungicides against Plasmopara viticola on vines and against Botrytis cinerea on apples. Compounds 5a-d showed weak to moderate activity as herbicides.