ИСТИНА

In the present report results of construction of new molecular switches on the basis of heterocyclic systems - a trans-3,4-dihydroxypiperidines and of them 3,4-trans-diacyloxy derivatives are presented. Protonation of trans-3,4-diacyloxy-1-benzylpiperidines lead to dramatic conformational changes: due to a strong intramolecular hydrogen bond, a conformer with axial positions of both acyloxy groups becomes strongly predominant. This conformational flip was studied by 1H NMR. It increases drastically the separation of the acyloxy groups thus altering their interactions. In case when substituents perform certain functions, e.g. as chelators or as lipid tails, the 3,4-disubstituted piperidine derivatives can serve as a powerful conformational pH-trigger.