A new access to efaroxan and its 5-amino derivatives

The formal total synthesis of racemic efaroxan, a 2-disubstituted 2,3-dihydrobenzofuran having interesting therapeutic properties, and the preparation of some 5-amino derivatives were achieved using a convergent approach. The key intermediates of both syntheses were obtained after a [3+2] cycloaddition reaction between two easily accessible partners.