Substitution and Michael reactions of bicyclic tetronic, tetramic and thiotetronic esters

Abstract

The 1,4-addition of several heteroatom and carbon nucleophiles to the bicyclic structures 1, 2, 3 and 13 are reported along with the conversion of the resultant adducts to substituted tetronic, tetramic, thiotetronic acids and butenolides; a novel reaction mechanism has been observed for the iodotrimethylsilane (TMSI) or acetic anhydride/magnesium bromide-mediated furan ring-opening reactions of the bicyclic tetronate 1.