(6) The analogous Cope rearrangements of 1, 5-~ yclononadienes and 13-cyclodecadienes, a four-carbon carbocyclic-carbocyclic ring-contraction process, have been well studied; see ref la. The anionic oxy-Cope ring contraction of cis, cis, cis-2, 4, 7-cyclononatrienol has recently been featured as the key step in the total synthesis of various cyclopentanoid natural products; see:(a) Paquette, LA; Crouse, GD Tetrahedron 1981, 37, supp 1, 28 I.(b) ...