Аннотация:Protonation of trans-3,4-diacetoxy-1-benzylpiperidine leads to dramatic conformational changes:
due to a strong intramolecular hydrogen bond, a conformer with axial positions of both acetoxy
groups becomes strongly predominant. This conformational flip was studied by 1H NMR. It
occurs while pH (pD) of the d4-methanol solution decreases from 6 to 3. As a result of the flip,
the separation of acetoxy groups increases drastically thus altering their interactions. For similar
structures with substituents designed to perform certain geometry-dependent functions, e.g. as
cation chelators or as lipid tails, an incorporated trans-3,4-disubstituted piperidine moiety can
serve as a powerful conformational pH-trigger of these functions.