1. For a review see Paquette, L. A., in: Nonbenzenoid Aromatics (ed.) Snyder, J. P., Vol. 1, p. 249 Academic Press, New York 1969; Paquette, L. A.: Angew. Chem. Int. Ed. Engl. 10, 11 (1971)
2. For reviews see Vogel, E., Günther, H.: Angew. Chem. Int. Ed. Engl. 6, 385 (1967); Rosowsky, A., in: Seven-Membered Heterocyclic Compounds Containing Oxygen and Sulfur (ed.) Rosowsky, A., Chapts. I–IV, Wiley-Interscience, New York 1972; Jerina, D. M., Yagi, H., Daly, J. W.: Heterocycles 1, 267 (1973)
3. For an attempted synthesis of parent thiepin see Barton, T. J., Martz, M. D., Zika, R. G.: J. Org. Chem. 37, 552 (1972)
4. Field, L., Tuleen, D. L., Traynelis, V. J., in: Seven-Membered Heterocyclic Compounds Containing Oxygen and Sulfur (ed.) Rosowsky, A., Chapts. X, XI, Wiley-Interscience, New York 1972; Eisner, U., Krishnamurthy, Int. J. Sulfur Chem. 6, 267 (1971); Reid, D. H.: Org. Compd. Sulfur, Selenium, Tellurium 1, 358 (1970); 2, 545 (1973); Eisner, U.: Org. Compd. Sulfur, Selenium, Tellurium 4, 332 (1977)
5. Traynelis, V. J., Livingston, Jr., J. R.: J. Org. Chem. 29, 1092 (1964)