Tetrahedron Letters,Vo1.24,No.36,pp 3869-3872,1983 0040-4039/83 $3.00 + .OO ... Chem., 121, C55 (1976) (4) a) M Tanaka, Tetrahedron Lett , 2601 (1979) ... c) T. Kobayashl and M Tanaka, J Chem Sot , Chem Commun , 333 (1981) (5) Org Syn Co1 Vol V, 855 (6) The migratory ...