... However, the yield of the addition product was increased by the choice of suitable solvents such as cyclohexane or benzene. In conclution, it is noted that TiCl4 is effectively used for the addition reaction of ethanethiol to various olefins under mild condition. REFERENCES 1) T. Mukaiyama, K. Kamio, S. Kobayashi, and H. Takei, Bull. Chem. Soc. Japan, 45, 3723 (1972); T. Mukaiyama, T. Imamoto, and S. Kobayashi, Chem. ...