Asymmetric synthesis of 2,3-disubstituted-1-benzoxepines is described. Key steps include Sharpless asymmetric dihydroxylation of trans-α,β-unsaturated esters and phenoxide ion-mediated intramolecular 7-endo-tet carbocyclization of syn-2,3-dihydroxy ester-derived cyclic sulphates.
