抄録
Stereochemistry of O-alkyl derivatives of N-9-triptycylhydroxylamine TpNHOR (R = CH2Ph, CH2Me) was studied by X-ray crystallography and dynamic NMR spectroscopy. Both compounds adopt a chiral conformation in crystal. In solution, two types of stereomutation processes are observed by NMR: chirality reversal and Tp-N rotation. Chirality reversal is observed as the lineshape change of the methylene proton signals and the lineshape analysis gives the free energy of activation of ca. 50 kJ/mol for both compounds, while the Tp-N rotation is observed as the lineshape change of the aromatic proton signals and the barrier is ca. 40 kJ/mol.
