Synthesis and Characterization of Novel Stilbenophanes: the Smallest Members of this Class of Compounds

The synthesis, properties and energy-optimized structure of stilbenophanes 1a–3a are reported. ¹H NMR spectroscopy of 1a shows it contains vinylic protons (unlike larger stilbenophanes), which appear as two doublets showing its unexpected configuration. Protons of the methylene bridge of 1b are also observed at different chemical shift, showing that they are diastereomeric protons. It is also found that the stereochemical outcome of the intramolecular McMurry reaction is strongly influenced by the length of the alkyl bridge.