1,3-Dipolar cycloaddition reactions of isothiazol-3(2H)-ones with nitrile oxides. An unexpected site selectivity of the carbonyl bond of 5-benzoyl-isothiazol-3(2H)-one

Article abstract of DOI:10.1002/jhet.5570330335

2,6-Dichlorobenzonitrile oxide (2a) reacts with isothiazolones 1a and 1b at the ethylenic double bond to give 4 via transformation of the primary cycloadducts 3. Mesitonitrile oxide (2b) adds preferentially to the carbonyl double bond of 1b yielding the m