Developments of new methods of NMR for stereochemistry of complicated chain structure compound s

为了观察长程JCH偶联和JHH偶联，我们研制了选择性J分辨HMBC、选择性COSY-J分辨HMBC和选择性J分辨HMQC。选择性J分辨HMBC测定长程C-H偶联（JC-H）在天然产物的立体化学研究中具有重要意义。J分辨HMBC-1方法是用于此目的的高灵敏度的首选方法。然而，由于H-H耦合和长程JC-H作用，交叉峰的形状变得复杂，导致难以分析复杂的自旋系统。为了克服与J分辨HMBC-1相关的这些问题，我们开发了一种新技术，选择性J分辨HMBC。在J分辨HMBC-1中引入质子-质子解耦的新方法，使其能够抑制JH-H耦合，并仅观察到具有短T2的复杂分子的长程C-H耦合。选择性COSY-J分辨HMBC我们提出了一种改进的方案，称为选择性COSY-J分辨HMBC。该方法增强了 ...更多信息 本发明提供了一种用于测定连接到J分辨HMBC或选择性J分辨HMBC中的甲基的次甲基质子信号的交叉峰的灵敏度的方法，并且能够确定其长程JCH偶联。J-分辨HMBC或选择性J-分辨HMBC被开发用于通过J-定标脉冲序列观察到HMBC中的长程JCH耦合。通过对模型化合物波特米星和莫那霉素的应用，证明了该方法适用于复杂分子的JC H的测定，选择性J分辨HMQC-H-J偶合常数的分析对天然有机化合物的相对立体化学研究具有重要意义。重叠质子或强耦合质子使H-H J耦合常数的分析变得困难。这个问题可以通过利用附着在13 C上的质子来解决。在强耦合的HA和HB自旋系统中，连接到13 C的HA和连接到12 C的HB构成弱耦合质子系统，导致HA和HB之间通过CA-HA J-耦合扩散的大化学位移差。因此，通过分析HA可以清楚地确定HA-HB J常数。为了克服这个问题，我们开发了一种新的方法，选择性J分辨HMQC通过去耦两个相邻的质子。将该方法应用于具有复杂结构的模型化合物单唑霉素的立体化学研究，证明了该方法的有效性。少

In order to observe long range JCH couplings and JHH couplings, we have developed Selective J-resolved HMBC, Selective COSY-J-resolved HMBC and Selective J-resolved-HMQC.Selective J-resolved HMBCDetermination of long-range C-H couplings (JC-H) is getting important for stereochemical studies of natural products. The J-resolved HMBC-1 method is a method of choice for this purpose with high sensitivity. The shapes of cross peaks, however, become complex by H-H couplings and long-range JC-H resulting in difficult analysis of complicated spin systems. In order to overcome these problems associated with J-resolved HMBC-1, we have developed a new technique, Selective J-resolved HMBC. The new method incorporating proton-proton decoupling into J-resolved HMBC-1 enables to suppress JH-H and to observe only long-range C-H couplings with complicated molecules having short T2.Selective COSY-J-resolved HMBCWe present an improved version named Selective COSY-J resolved HMBC. This method enhances the … More sensitivity of cross peaks of methine proton signals attached to a methyl group in J-resolved HMBC or Selective J-resolved HMBC, and enables to determine its long range JCH couplings. J-resolved HMBC or Selective J-resolved HMBC were developed for observation of long range JCH couplings by the J-scaling pulse sequence into HMBC. Application of this new technique to model compounds, portmicin and monazomycin, proved that this method is useful for determination of JC H of complicated molecules.Selective J-resolved HMQCAnalysis of H-H J coupling constants is important for relative stereochemical studies of natural organic compounds. Overlapping protons or strongly coupled protons make analysis of H-H J coupling constant difficult. This problem can be solved by utilizing a proton attached to 13C. In a strongly coupled HA and HB spin system, HA attached to 13C and HB connected to 12C constitute a week coupled proton system resulting in a large chemical shift difference between HA and HB spread by CA-HA J-coupling. Thus the HA-HB J constant can be clearly determined by analyzing HA. In order to overcome this problem, we developed a new method, selective J-resolved HMQC by decoupling two adjacent protons. Application of this method to a model compound, monazomycin with a complicated structure proved its effectiveness for stereochemical studies. Less