SEARCH Articles Figures Tables Klemm, L. H., Syntheses of Tetracyclic and Pentacyclic Condensed Thiophene Systems Of tetracyclic and pentacyclic condensed thiophene systems Synthesis, of tetracyclic and pentacyclic condensed thiophene systems Tetracycles Tetracyclic Tetracyclic ring system Tetracyclic ring system, highly Tetracyclics Tetracyclization