Thienopentathiepins and pentathiepinofuran were synthesised by the reaction of thiophenes and 2,5-dimethylfuran with S2Cl2 and N-ethyldiisopropylamine in chloroform at low temperature; thienopentathiepin 2 reacts with methyl propiolate and triphenylphosphine to give a pair of regioisomers.