1, 2-Bis (phenylethyny1) benzene (1) reacts with sulfur, carbon monoxide, and acetylenedicarboxylic esters to give unusual polycyclic products. Under exclusion of air 1 adds sulfur to give 6-phenylbenz [b] indeno [2, 1-d] thiopyran (3b) and bis (6-phenylbenz [b] indeno [2, 1-djthiopyran-ll-y1) disulfide (4). In the presence of air 3-benzoyl-2-phenyl-lH- inden-1-one (5) is formed via a sulfur-containing intermediate. Under phasetransfer ...