(1) E. ROTHSTEIN and J. F. THORPE, J. Chem. SOC., 201 1 (1926). (2) A. MAEDER, Helu. Chim. Acta, 29, 120, 983 (1946). (3) RB WOODWARD and ER BLOUT, J. Am. Chem. Soc., 65,562 (1943). (4) M. ORCHIN and LW BUTZ, J. Am. Chem. SOC., 65,2296 (1943). (6) JS BURTON, JA ELVIDGE and R. STEVENS, J. Chem SOC., 1276 (1965). (6) J. PANOUSE and C. SANNI~, Bull. SOC. Chim. Fr., 1036 (1955). (7) JA ELVIDOE and R. STEVENS, J. Chem. ...