... R. Bloch, E. Guibeampel and C. Girard Laboratoire des Carbocycles, UA CNRS 478, Biment 420 Universitde Parisud, 91405 ORSAY CEDEX, France Abstract. ... Soc., Chem. Comm., 1984, 579 ~i~I references therein ; e) F. Van Middlesworth, Y. Wang, B. Zhou, D. DiTullio and CJ Sih, Tetrahedron Lett., 1985, 26, 961 ; f) P. Mohr, N. Waespearcevic, C. Tamm, K. Gawronska and JK Gawronski, Rely. Chim. Acta, 1983, 66, 2501. ...