1. N. Kharasch, in “Organic Sulfur Compounds,” Vol. 1, N. Kharasch, Ed., Pergamon Press, New York (1961); G. H. Schmid and D. G. Garratt, in “The Chemistry of Functional Groups: The Chemistry of Double-bonded Functional Groups, Supplement A,” Part 2, S. Patai, Ed., Wiley, London (1977).
2. L. Maioli, G. Modena, and F. Taddei,Boll. Sci. Fac. Chim. Ind. Bologna,18, 58 (1960); G. Modena and G. Scorrano,Mechanism of Reaction of Sulfur Compounds,3, 115 (1968).
3. For relevant reviews see: G. Modena and U. Tonellato,Adv. Phys. Org. Chem.,9, 185 (1971); P. J. Stang,Progr. Phys. Org. Chem.,10, 205 (1973); L. R. Subramanian and M. Hanack,J. Chem. Educ.,52, 80 (1975); H. G. Richey and J. M. Richey, in “Carbonium Ions,” Vol. 2, G. A. Olah and P. von R. Schleyer, Eds, Wiley, New York (1970).
4. C. A. Grob and C. Cseh,Helv. Chim. Acta,47, 194 (1964).
5. V. Calo’, G. Modena, and G. Scorrano,J. Chem. Soc., (C),1344 (1968).