1. For a recent application of the Hinsberg reaction, see D. J. Chadwick, J. Chamvers, G. D. Meakins and R. L. Snowden, J. Chem. Soc., Perkin Trans. 1, 2079 (1972).
2. Synthetische Versuche mit Thiodiglykolsäureester
3. a J. D. Loudon and A. D. B. Sloan, J. Chem. Soc., 3362 (1962).
4. b E. F. Godefroi, A. Corvers and A. de Groot, Tetrahedron Letters, 2173 (1972).
5. Benzoheterocyclic synthesis via benzoannelation of heterocyclic ortho-dicarboxaldehydes: Benzimidazoles from an imidazole-4,5-dicarboxaldehyde; a benzo[b]furan from a furan-2,3-dicarboxaldehyde