1H and13C NMR assignments of conformationally defined 6- s-cis-retinoids

Abstract

Three examples of a new class of retinoic acid analogs (retinoids) were synthesized. These retinoids contain a dimethylene bridge to maintain a 6‐s‐cis conformation of the terminal double bonds, which is preferred in the major conformation of the natural compound. The 1H and 13C NMR spectra were assigned for 22 new compounds, including retinoid E/Z isomers (all‐ E, 13Z, 9Z) and selected intermediates. The assignments were based upon long‐range 1H– 13C heteronuclear 2D experiments. © 1999 John Wiley & Sons, Ltd.