CHIRAL SPIROCYCLIC BENZOPYRAN POTASSIUM CHANNEL OPENERS - EVIDENCE FOR THE ACTIVE CONFORMATION OF LEVCROMAKALIM

Both enantiomers of a spirocyclic benzopyran imidazolone were prepared in high enantiomeric purity. The S-isomer was found to be a potent po tassium channel opener while the R-isomer was completely inactive. Com parison of this structurally rigid compound with levcromakalim suggest s that the biologically active conformation of levcromakalim is the sa me as its preferred conformation in solution and solid state.