Synthesis of new spiro-isothiochromene-3,5 '-isoxazolidin-4(1H-ones

摘要

A series of seven new 2',3',4'-substituted spiroisothiochromene-3,5'-isoxazolidin-4(IH)-ones (7-13) has kbeen prepared in the reaction of benzylidene(phenyl) azane oxide (5) or benzylidene(methyl) azane oxide (6) with (3Z)-3-(4-substituted-benzylidene)-1H-isothio-chromen-4(3H)-one(1-4). The reaction occurs by a 1,3-dipolar cycloaddition mechanism that leads to the regiospecific formation of various spiroisoxazolidines (7-13).