2,3,6,7-tetrasubstituted decalins: Biconformational transducers for molecular signal transduction

2,3,6,7-Tetrasubstituted decalins of relative configuration (2 beta ,3 alph a ,4a alpha ,6 alpha ,7 beta ,8a alpha) have been synthesized. If substitue nts as in 6 are chosen, the equilibrium of the biconformational system 2/3 is shifted towards conformer 2. Conversion into the bis(acetal) 16 resulted in a covalently induced double ring flip 17 --> 18. A chelation-induced do uble ring flip (21 --> 22) was achieved when 2,2'-bipyridyl substituents we re attached by ether linkages at the receptor positions 6 and 7 of the deca lin system. Effector groups were introduced by adding pyrene groups, throug h an (E)-olefin Linker, in positions 2 and 3. The resulting compound 25 pro ved to be an effective device for molecular signal transduction over a sign al distance of 1.5 nm. A zinc signal caused a conformational axial-to-equat orial change at the receptor site, which was transduced by a double ring fl ip of the decalin moiety (28 --> 29) to the pyrene effector site, where the induced equatorial-to-axial flip induced a characteristic fluorescence pea k.