Abstract Various types of 1, 2, 3, 4-pentatetraenes 4 and 1, 2, 3, 4-pentatetraene episulfides (1 and 2) were synthesized readily and selectively by the alkenylidene carbene addition to thioketene. Thermal, photochemical, and acid-promoted reactions of 1 and 2 resulted in a formation of novel conjugated thiones 5 and 6.
