... 3; (a) C. Gennari, L. Colombo, S. Cardani, C. Scolastico; Tetrahedron Letters (1984), p. 2283. ... b) C. Gennari, A. Bernardi, S. Cardani, C. Scolastico, Tetrahedron, in press. 4; CH Heathcock; ,in: JD Morrison (Ed.), Asymmetric Synthesis, 3Academic Press (1984), pp. 136–144 and references therein. ...