核磁共振解析2.ppt

2D NMR 图谱,结构鉴定: 化合物2-1,H-21a,H-21b,H-4,H-3,Me-23,Me-20,1H NMR of 2-1,H-2,C-1,C-22,C-9,C-10,C-4,C-21,C-3,C-19,C-20,13C NMR of 2-1,C-2,H-4,H-3,H-2,Me-20,H-18,H-15,H-14,H-13a,H-16a,H-17a,H-6,H-7a,1H,1H-COSY,H-11a,H-12a,HMBC （高场区）,C-3,C-7,H-19a,H-3,C-2,C-18,Me-20,C-19,H-21a,H-21b,C-8,C-6,C-5,H-4,检测的是核与核之间的关系,Direct H-C correlations (HSQC) Interaction between H and C atoms through one bond.,1JC-H correlations,C-1,H-1,Spectrum 13C,1H Spectrum,1H-1H correlations (COSY) Proton interaction trough three bonds.,3JH-H correlations,H-1,H-2,Spectrum 1,Spectrum 1,适用于重叠峰耦合的判断,Long-range 13C-1H correlations (HMBC). Interaction between 13 and 1 nuclei trough two and three bonds.,HMBC peaks corresponding to 2- and 3-bonds correlations are undistinguishable!,-1,H-i H-k,Spectrum 13,Spectrum 1,Nuclear Overhauser Effect (NOE),Interaction between 1H-1 and 1H-2 when they are distanced in the space by r 5 Å. NOE produced NOESY / ROESY 2D NMR spectra.,r,2D NMR图谱的解析,Organic Structure Analysis, Crews, Rodriguez and Jaspars,STRATEGY BASED ON C-H CONNECTIVITY,&,&,HMBC data is ambiguous (2 or 3 bond correlations impossible to tell which),Organic Structure Analysis, Crews, Rodriguez and Jaspars,STRATEGY BASED ON C-H CONNECTIVITY HSQC DATA,A B C D E F dC,a,b,c,d,d,e,f,label protons in lower case letters,Organic Structure Analysis, Crews, Rodriguez and Jaspars,STRATEGY BASED ON C-H CONNECTIVITY HSQC DATA,Organic Structure Analysis, Crews, Rodriguez and Jaspars,STRATEGY BASED ON C-H CONNECTIVITY HSQC DATA,Organic Structure Analysis, Crews, Rodriguez and Jaspars,STRATEGY BASED ON C-H CONNECTIVITY HSQC DATA,Organic Structure Analysis, Crews, Rodriguez and Jaspars,STRATEGY BASED ON C-H CONNECTIVITY HSQC DATA,Organic Structure Analysis, Crews, Rodriguez and Jaspars,STRATEGY BASED ON C-H CONNECTIVITY HSQC DATA,diastereotopic protons,为什么没有C-C相关谱？,天然丰度低，1%，相关的几率1/10000 需要大量的样品，要求溶解性极高 需要很长的累积（次数）时间,