Ring-Opening 1,3-Halochalcogenation of Cyclopropane Dicarboxylates

Donor acceptor cyclopropanes with two geminal carboxylic esters are reacted with chalcolgenyl chlorides and bromides to afford ring-opened products bearing the halogen atoms in the 1, position;, adjacent to the donor, and the chalcogenyl residue in the 3-position next to the two acceptor groups. A variety of different donors (e.g., aryl, N, and O) are used. The stereospecificity of the reaction is demonstrated by using a chiral starting Material.