Highly convergent total synthesis of (+)-anaferine and (-)-dihydrocucohygrine

A unified and highly convergent total synthesis of anaferine and dihydrocuscohygrine alkaloids has been devised, taking advantage of the dual role of N-sulfinyl amines as nucleophilic nitrogen sources and chiral auxiliaries. A bidirectional cross metathesis reaction followed by a double intramolecular aza-Michael reaction led us to create the whole skeleton of the natural products in a very simple manner