用NOE差谱和二维核磁共振技术研究3S-取代烷氧基-奎宁环烷的立体化学

用3S-奎宁环醇与环氧化合物反应,得到化合物(Ⅰ)的二个光学异构体(3S-1)和(3S-2)。它们的生物活性有明显差别。本文采用NOE差谱和二维NMR技术指定了各异构体的^{1H和13C信号的归属,确定了它们的溶液态构象,测定了其C-11的绝对构型,并且阐明了立体结构与生物活性间的关系。C-11绝对构型的测定结果经X-射线衍射测定进一步得以肯定。}

1H,13C NMR AND STEREOCHEMISTRY STUDIES OF 3SSUBSTITUTED ALKOXYLQUINUCLIDINE BY TWO-DIMENSIONAL AND NOE DIFFERENCE NMR TECHNIQUES

By using optically pure 3S-quinuclidinol, two diastereoisomers(3S-1) and (3S-2) of 3-(substituted) alkoxy-quinuclidine were synthesized. ~1H and ~(13)C NMR spectra of (3S-1) and (3S-2) have been completely analyzed utilizing doudlequantum filtered COSY, ~(13)C-~1H COSY and NOE difference experiment. The NOE difference experiment was used to determine the absolute configuration at C-11 of the diastereomers. According to the results of NOE difference and variable concentration NMR experiments, the configuration about C-11 of (3S-1) is designated as R (1A), whereas the configuration about C-11 of (3S-2) is designated as S (1B). The result was confirmed by X-ray diffraction analysis.