Reaction of 3,4-disubstituted 1,2,5-oxadiazole 2-oxides with dipolarophiles. Substituent and solvent effect on the reaction courses

Article abstract of DOI:10.1016/S0040-4020(01)96450-6

A variety of symmetrically or unsymmetrically 3,4-disubstituttd furoxans such as dicyano, dialkyl, diacyl, bis(phenylsulfonyl), N.N'-dialkyldicarbamoyl, 3(or 4)-methyl-4(or -3)-phenyl(or nitro, ethoxy, phenoxy, phenylthio, pyrrolidinyl, phenylsulfonyl), 3