Sulfur-mediated synthesis and antimicrobial activity of 4-thioisosteres of flavanoids

摘要

Each step of the synthetic sequence inverse electron-demand hetero-Diels-Alder reaction of omicron-thioquinones with styrenes,oxidation at sulfur,and Pummerer rearrangement allowed the preparation of 4-thioisosteres of flavanoids,namely thiaflavans,thiaflavanones and thiaflavanols.A preliminary screening indicates a clear,though moderate,antimicrobial activity of such compounds that depends upon the substitution pattern and the oxidation state at sulfur.