聚醚型化合物的核磁共振碳谱解析

论述了以环氧乙烷、环氧丙烷为代表的聚醚型化合物的核磁共振碳谱特点及其立构规整性特征，并通过对主链碳谱和末端基碳谱的解析，讨论了聚合反应机理和聚合物组成。     

2-O-乙酰和3-O-乙酰-4,6-苯亚甲基-α-D葡萄糖甲甙的核磁共振鉴别法

本文报告了用同核相关二维核磁共振氢谱和核磁共振碳谱两种核磁共振方法来鉴别氟代去氧六碳糖化合物合成中关键性中间体2-O-乙酰和3-O-乙酰-α-D-4,6-苯亚甲基葡萄糖甲甙的结果。     

二维NMR技术在有机结构分析中的应用

联合应用二维远程碳 -氢相关 (coloc)技术和二维碳 -氢相关(hxdept)技术 ,对三个含季碳较多的化合物进行了谱峰归属与结构指定。从而显示出多维NMR技术在有机结构分析中的重要作用。     

吲哚二碳菁染料的合成

合成了五种N－烷基吲哚二碳菁染料，通过质谱、核磁共振氢谱及红外光谱确证了化合物结构。测定了化合物在溶液中的紫外吸收光谱和溶解度，讨论了溶解度、熔点与染料分子结构的关系。     

4—叠氮—4—脱氧—4‘—去甲基表鬼臼毒素的^1H和^13C核磁共振分析

用＾１Ｈ－＾１ＨＣＯＳＹ，ＨＭＱＣ和ＲＯＥＳＹ二维核磁共振等技术对标题化合物的氢谱和碳谱进行了完全归属。     

3种聚酰亚胺分子的核磁共振碳谱及氢谱的分析

本文报道了３种高性能聚酰亚胺的核磁共振定量碳谱及氢谱。利用这３种样品化学结构的相似性，根据ＰＥＩ和ＤＥＰＴ谱，ＰＥＩ和ＰＯＩ的二维同核化学位移相关谱，碳氢自旋晶格驰豫时间以及化学位移的理论计算，详细分析并归属了３种聚酰亚胺的碳谱峰和氢谱峰，同时验证了其重复单元结构的正确性。     

相敏远程碳-氢相关技术在季碳归属中的应用

基于作者的二维相敏INEPT（insensitive nuclei enhanced by polarization transfer）实验,提出了相敏模式的远程碳－氢相关实验,称为相敏COLOC（heteronuclear correlation via logn-range couplings）实验,改善了远程碳－氢相关（COLOC）谱的分辨率。相敏COLOC实验可用于测定远程碳－氢相关信息,对季碳化学位移的归属具有一定的意义。作者给出了头孢呋辛钠的相敏COLOC谱。     

1,5-二氮杂二环[4.3.0]-壬-5-烯与全氟烷基炔酸甲酯的Michael加成反应

1,5-二氮杂二环[4．3．0]-壬-5-烯(DBN)与全氟烷基炔酸甲酯发生Michael加成反应,生成的中间体发生分子内缩合产生了三环化合物。其结构经元素分析,IR,MS和核磁共振氢谱、碳谱,二维核磁共振^13C-^1H cosy谱,二维核磁共振^1H-^1H cosy谱确认。对反应机理也进行了探讨。     

正丁基锂的直接碳谱测试与简易浓度定量探讨

1　引　　言核磁共振振碳谱是研究有机化合物强有力的工具。我们曾探讨不用氘代试剂且不经处理直接测试化合物碳谱的方法 ,本文中我们报告应用此方法来定量正丁基锂的浓度。正丁基锂的性质活泼易与空气反应 ,因此制备与储存均在乙醚等隋性溶液中进行。正丁基锂制备后以及长时间储存 ,使用前需要标定浓度 ,目前多采滴定法 ,经过两次滴定由公式推算得到浓度数据。本文探讨使用直接核磁共振碳谱对正丁基锂的浓度制定标准曲线图的可行性 ,实验表明使用标准曲线法可通过碳谱积分数据对正丁基锂的浓度进行定量分析。为了解碳谱分子间碳峰积分比值…     

青蒿素的二维核磁共振研究

报导了采用二维核磁共振技术研究青蒿素的核磁氢谱和碳谱的谱线归属,以今后为^1^3C中间体的生物转化产物提供鉴定的基础.     

稻秆木素侧链13C同位素示踪及固体13CNMR分析

在水稻(Oryza sativa L.)生长过程中,向其茎秆部节间的空腔分别注入在侧链α,β,γ位带有¹³C标记的松柏醇葡萄糖甙,得到¹³C标记的稻秆木素,用高分辨率固体核磁¹³CNMR对其组织进行分析,发现外源性的松柏醇葡萄糖甙并不影响水稻中木素的正常合成.证明了β-O-4,β-β,β-5和β-1结构是稻秆原本木素中的主要结构,另外还有少量的松柏醇和阿魏酸类结构,并证实木素在α位与糖类等组分有共价键形成.     

NMR studies on 1,2‐dihydro‐2‐(4‐aminophenyl)‐4‐[4‐(4‐aminophenoxy)‐4‐phenyl]‐(2H)phthalazin‐1‐one

An unsymmetrical heterocyclic diamine, 1,2‐dihydro‐2‐(4‐aminophenyl)‐4‐[4‐(4‐aminophenoxy)‐4‐phenyl]‐(2H)phthalazin‐1‐one, was synthesized. Its ¹H and ¹³C NMR spectra were completely assigned by utilizing the two‐dimensional heteronuclear ¹³C–¹H multiple‐bond coherence (HMBC) spectroscopy, and heteronuclear ¹³C–¹H one‐bond correlation spectroscopy, homonuclear shift correlation spectroscopy (H,H‐COSY) and rotating frame Overhauser enhancement spectroscopy (ROESY). The structure of the compound was shown to be the phthalazinone rather than the phthalazine ether from cross peaks and chemical shifts of the protons. Copyright © 2002 John Wiley & Sons, Ltd.     

Prediction of the 13C NMR Chemical Shifts of Fluorenone Analogues by the GIAO Method

After the geometry optimization at B3LYP/6-31+G(d,p) level,the NMR calcula-tions of a series of fluorenone analogues have been carried out by GIAO method at HF/6-31+G(d) level and B3LYP/6-311G+(2d,p) level,respectively.The 13C NMR chemical shifts calculated at HF/6-31+G(d) level show better agreement with the observed values.By a series of linear correction equations (δpred=a + bδcalc),accurate prediction of 13C chemical shifts was achieved for the new fluorenone compound.The linear correlation of δpred with δexptl is excellent,and the square of correlation coefficient,r2,is up to 0.994.The maximum absolute difference between δpred and δexptl,Δδ,is 4.6 ppm,and the root-mean-square error between δpred and δexptl is only 2.6 ppm.     

Natural-abundance 15N--13C correlation spectra of vitamin B-12

Two-dimensional nitrogen-carbon NMR correlation spectra have been derived by a new reconstruction technique based on standard two-dimensional HMQC and HMBC spectra, and operating with natural 15N and 13C isotopic abundances. Compared with conventional three-dimensional spectroscopy in which 15N and 13C spins must be present in the same molecule, the reconstruction method offers two orders of magnitude improvement in sensitivity. Vitamin B-12 serves as an illustrative example.     

Total Synthesis of Phakellistatin 13 by Solution Method

Since George R. Pettit’s group isolated cycloheptapeptide phakellistatin 1 from sponge1, over ten similar cyclic peptides have been obtained2-5. Phakellistatin 134 (Figure 1) is a cycloheptapeptide isolated from the brown snubby sponge from the South Chi…     

Prediction of the ~(13)C NMR Chemical Shifts of 9,10-Dihydrophenanthrene Analogues by the GIAO Method

After the geometry optimizations at the B3LYP/6-31+G(d,p) level, the NMR calculations of a series of 9,10-dihydrophenanthrene analogues have been carried out by GIAO method at the HF/6-31+G(d) level. The calculated 13C NMR chemical shifts are in agreement with the observed values. By a series of linear correlation equations (δpred = a + bδcal.c) of the 13C chemical shifts, accurate prediction of 13C chemical shifts was achieved for the new 9,10- dihydrophenanthrene compound, for which the predicted 13C NMR chemical shifts are in quite good agreement with the experimental values. The linear correlation between δpred and δexptl is excellent, and the square of correlation coefficient, r2, is up to 0.9973. The maximum absolute difference between δpred and δexptl, Δδ, is 4.5 ppm, and the rms error between δpred and δexptl is 2.55 ppm. In the meantime, according to the theoretical predicted result, we could confirm that the new 9,10-dihydrophenanthrene analogue is erianthridin (2,7-dihydroxy-3,4-dimethoxy-9,10-dihydro-phenanthrene).     

Assignments of 1H and 13C NMR spectral data for ondansetron and its two novel metabolites, 1-hydroxy-ondansetron diastereoisomers

Assignments of 1H and 13C NMR chemical shifts were made by means of heteronuclear single quantum coherence (HSQC) and heteronuclear multiple bond correlation (HMBC) experiments for ondansetron, and by means of 1H-1H correlation spectroscopy (1H-1H COSY) and two-dimensional nuclear Overhauser effect spectroscopy (NOESY) experiments for two novel metabolites (M1 and M2) of ondansetron. These two metabolites were isolated for the first time from Mucor circinelloides.     

西尼地平核磁共振碳谱氢谱的谱峰归属

利用普通1H-NMR，13C-NMR，极化转移谱(DEPT)以及同核相关谱(COSY)、异核相关谱(HSQC)，特别是远程偶合谱(HMBC)等多种核磁研究方法对新型的血管扩张药西尼地平的1H、13C信号进行完全归属。对由于分子结构对称而引起的化学位移相差最小为0．94Hz的两个碳加以区分，解决了由于样品的近似对称性而导致几组谱峰难以归属的问题。     

13C nuclear magnetic resonance spectroscopy for determining the different components of epicuticular waxes of olive fruit (Olea europaea) Dritta cultivar

¹³C nuclear magnetic resonance spectroscopy (NMR) was applied to determine the different components of apolar and polar fractions which were isolated by column chromatography from the crude chloroform-soluble waxes of olive fruits (Olea europaea) Dritta cultivar.¹³C NMR enabled the determination in the wax apolar fraction, of aliphatic aldehydes, and of benzyl, alkyl and glyceryl esters. In particular, the fatty acid composition of alkyl esters, comprising saturated and unsaturated oleic and linoleic acids, was determined. Acyl chain composition and the chain composition of 1,3- and 2-glycerol positions were also determined for triacylglycerols of olive fruit waxes.Oleanolic and maslinic acids were confirmed to be the major components of wax polar fraction. Complete assignments of ¹³C NMR chemical shifts of oleanolic and maslinic acids as a mixture were achieved by using homonuclear correlation spectroscopy with gradient (g-COSY), attached proton test (APT), inverse-detected heteronuclear single-quantum coherence with gradient (g-HSQC), high-resolution heteronuclear correlation spectroscopy (HETCOR) for C-H directly attached pairs and C-H long-range-coupled experiments.     

Complete 1H and 13C NMR spectral assignment of symmetric and asymmetric bis-spiropyran derivatives

(1)H and (13)C NMR spectra of symmetric and asymmetric bis-spiropyrans, Series 1-3, were completely assigned. Especially, the (1)H assignment of asymmetric spiropyrans was achieved by utilizing (1)H-(1)H COSY and nOe experiments. All of the carbons in the dye molecules were investigated through a combination of heteronuclear 2D-shift correlation spectroscopy (HETCOR), together with an attached proton test (APT).