Reactions of Ph2C3 dianion with alkyl thiocyanates or ethylene 1,2-dit
hiocyanate give 1,3-bis(alkylthio)allenes or tetrathiacyclic bisallene
, respectively. Thermal reactions of 1,3-bis(benzylthio)allene and tet
rathiacyclic bisallene afford 2,3,5-triphenylthiophene and 1,2-bismeth
ylidene cyclobutane derivatives, respectively. (C) 1997 Elsevier Scien
ce Ltd.