H-1 and C-13 NMR assignments of conformationally defined 6-s-cis-retinoids

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