1. Untersuchungen über synthetische Arzneimittel 9- und 10-Oxo-Derivate von 9,10-Dihydro-4H-benzo[4,5]cyclohepta-[1,2-b]thiophenen
2. Keto-tautomerism in the thiophene analogs of anthrone. I. Derivatives of naphtho[2,3-b]thiophene and naphtho[2,3-c]thiophene
3. The 2-thienoyl moiety can be easily introduced by Fridel-Crafts acylation of thiophene; see refs [2], [6], [7].
4. Y.-H. Lai, Synthesis, 586 (1981), and lit cited therein.
5. Synthesis and Diels-Alder reactions of anthra[2,3-b]thiophene