Fused isothiazole S-oxide systems from cycloaddition reactions of N-benzylisothiazol-3-amine 1-oxide

Abstract

The racemic N-benzylisothiazol-3-amine 1-oxide (2) was demonstrated to be an efficient partner in Diels-Alder reactions (Schemes 2-4) and a good dipolarophile in 1,3-dipolar cycloaddition reactions with nitrile oxides (Scheme 5). Polycyclic isothiazole S-oxides with different substitution patterns were obtained from 2 in good yield and in a fully regioselective way. Improved diastereoselection was observed performing the Diels-Alder or 1,3-dipolar cycloaddition reactions in H 2O. © 2009 Verlag Helvetica Chimica Acta AG.