Synthesis and Reactions of 4,5-Dihydro-2(3H)-thiophenethione.-The title compound (II) is prepared by sulfuration of the oxo analogue (I) with a reagent prepared in situ from P4S10 and MeOH. -(KURIHARA, H.; KOBAYASHI, A.; KUMAMOTO, T.; Nippon Kagaku Kaishi (1996) 10, 875-881; Dep. Chem., Fac. Sci., Tokai Univ., Hiratsuka 259-12, Japan; JA)