Silver‐Catalyzed Asymmetric Synthesis of 2,3‐Dihydrobenzofurans: A New Chiral Synthesis of Pterocarpans

2,3‐Dihydrobenzofurans can be diastereoselectively prepared by condensation of aromatic aldehydes with 2,3‐dihydrobenzoxasilepines under the catalysis of Ag I complexes, and in the presence of a source of fluoride ion. The application of this strategy by using chiral catalysts leads to a new enantioselective total synthesis of natural cis ‐pterocarpans and their trans isomers. Through this method, the first enantioselective total synthesis of the antifungal agent (−)‐pterocarpin was achieved. In addition, a new entry into the heteroaromatic system of 2,5‐dihydrobenzoxepine is also presented.