2,3,6,7-Tetrasubstituted Decalins: Biconformational Transducers for Molecular Signal Transduction

2,3,6,7-Tetrasubstituted decalins of relative configuration (2β,3α,4aα,6α,7β,8aα) have been synthesized. If substituents 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 double ring flip (21 22) was achieved when 2,2′-bipyridyl substituents were attached by ether linkages at the receptor positions 6 and 7 of the decalin system. Effector groups were introduced by adding pyrene groups, through an (E)-olefin linker, in positions 2 and 3. The resulting compound 25 proved to be an effective device for molecular signal transduction over a signal distance of 1.5 nm. A zinc signal caused a conformational axial-to-equatorial change at the receptor site, which was transduced by a double ring flip of the decalin moiety (28 29) to the pyrene effector site, where the induced equatorial-to-axial flip induced a characteristic fluorescence peak.