“…A number of papers have been published on the conformations of a,fl-unsaturated ketone derivatives. Some of the ketone derivatives are obtained either as the s-cis or as the s-trans form, mainly because of the steric and/or packing effect (Noack & Jones, 1961;Jungk & Schmidt, 1970;Ohkura, Kashino & Haisa, 1973;Rabinovich & Shakked, 1974), and others exist as equilibrium mixtures of different conformers at least in solution (Fuson, Josien & Shelton, 1954;Kronenberg & Havinga, 1965;Hayes & Timmons, 1968;Dimmock, Carter & Ralph, 1968;Silver & Boykin, 1970;Winecoff& Boykin, 1972).…”