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.
[Chapleo, Christopher B.; Myers, Peter L.; Butler, Richard C. M.; Davis, John A.; Doxey, John C.; et al. Journal of Medicinal Chemistry, 1984 , vol. 27, # 5 p. 570 - 576]