(1) Presented in part at the 159th National Meeting of the American Chemical Societv Houston. Texas. Feb 1970. For example, se%(a) EJ'Coreyand~ GH Posner, J. Amer. Chem. SOC., 89, 3911 (1967);(b) GM Whitesides, et ai., ibid., 91, 4871 (1969);(c) A. i. Meyers, et ai., J. Org. Chem., 38, 36 (1973);(d) JA Katzenellenbogen and RS Lenox, ibid., 38, 326 (1973):(e) LH Sommer and WD Korte, ibid., 35, 22 (1970);(f) RJ Crawford, WF Erman, and ...