The detailed conformational study of a leukotriene antagonist, FPL-55712, using high-field nuclear magnetic resonance spectroscopy. 
High-field proton magnetic resonance measurements at 400 MHz and 600 MHz allowed the evaluation of the preferred conformations of a leukotriene antagonist, FPL-55712.  The experiments involved an analysis of proton-proton coupling constants, longitudinal relaxation time data and nuclear Overhauser effect experiments.  The NMR parameters confirm the conformational features expected from X-ray and microwave data for related substances, such as rotational freedom about C14-C15 and C15-C16, synperiplanar arrangements for C7-C8-O-C14 and C16-O-C17-C18 and segmental motion in the propyl side chains.