共查询到20条相似文献,搜索用时 140 毫秒
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本文采用氢氟酸吡啶鎓在5′-位选择性断裂1,1,3,3-四异丙基二硅氧烷基保护基的方法得到了核苷衍生物N-异丁酰基-3′-O-(1-氟-1,1,3,3-四异丙基-1,3-二硅氧烷-3-基)-2′-苄氧羰基鸟苷(化合物1),并应用液相色谱串联质谱(LC-MS)、气相色谱-高分辨质谱(GC-HRMS)、液体1D和2D NMR谱(包括1H NMR、13C NMR、19F NMR、DEPT、1H-1H COSY、1H-13C HSQC和1H-13C HMBC),对产物的1H、13C和19F NMR信号进行了归属,确定了其结构. 相似文献
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以连翘脂素和布洛芬为原料,通过Schotten-Baumann酯化合成了酯合物——连翘脂素-布洛芬酯.对其紫外吸收光谱(UV)、红外吸收光谱(IR)、基质辅助激光解吸/电离飞行时间质谱(MALDI-TOF-MS)、1D和2D核磁共振(NMR)波谱(包括1H NMR、13C NMR、DEPT、1H-1H COSY、1H-1H NOESY、1H-13C HSQC和1H-13C HMBC)进行了解析,对其1H和13C NMR谱峰进行了全归属. 相似文献
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用一维1H、13C NMR谱、DEPT 13C NMR谱、选择性远程DEPT 13C NMR、1H-1H COSY和13C-1H COSY二维核磁共振技术研究了南海海绵Dysidea fragilis中的两个倍半萜herbadysidolide(1)和furodysinin lactone(2),确认了化学结构,并对其13C NMR和1H NMR谱进行了归属.药理活性试验表明:1和2具有一定的心血管活性. 相似文献
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利用1H NMR、13C NMR、COSY、HSQC和HMBC等多种核磁共振技术,结合MS技术,确认了皂苷Tb的2个糖基化产物的结构,即偏诺皂苷元-3-O-α-D-葡萄糖-(1→3)[α-L-鼠李糖(1→2)]-β-D-葡萄糖苷(1)和偏诺皂苷元-3-O-α-D-葡萄糖-(1→4)-α-D-葡萄糖-(1→3)[α-L-鼠李糖-(1→2)]-β-D-葡萄糖苷(2). 化合物1和2为新化合物,对其1H NMR和13C NMR信号分别进行了全归属和详细分析. 相似文献
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Norma N. Buceta Diego Ruiz Gustavo P. Romanelli Juan C. Autino Helmut Duddeck Reinaldo Pis Diez Jorge L. Jios 《Journal of Physical Organic Chemistry》2014,27(2):106-113
The experimental 1H and 13C NMR spectra of 13 phenyl cinnamates and four 4‐methylcoumarins were investigated and their chemical shifts assigned on the basis of the two‐dimensional spectra. For the unsubstituted cinnamic acid phenyl ester, optimized molecular structures were calculated at a B3LYP/6‐311++G(d,p) level of theory. 1H and 13C NMR chemical shifts were also calculated with the GIAO method at the B3LYP/6‐311 + G(2d,p) level of theory. The comparison between experimental and calculated NMR chemical shift suggests that the experimental spectra are formed from the superposition spectra of the two lowest energy conformers of the compound in solution. The most stable s‐cis configuration found in our studies is also the conformation adopted for a related phenyl cinnamate in solid state. The experimental results were analyzed in terms of the substituent effects. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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扁枝藓中锯齿石松烷型三萜的NMR化学位移全归属 总被引:2,自引:0,他引:2
从扁枝藓(Homalia trichomanoides)中分得了三个锯齿石松烷型三萜化合物: 3α-甲氧基-锯齿石松-14-烯-21β-醇(1)、3β-甲氧基-锯齿石松-14-烯-21β-醇(2)和3β-甲氧基-锯齿石松-14-烯-21-酮(3), 应用1D和各种2D NMR实验技术(包括1H-1H COSY, HMQC和HMBC)对化合物结构进行了研究, 对1H和13C化学位移进行了完全归属, 并根据1H NMR中信号的裂分对三个化合物C-3位与1和2的C-21位的立体构型作出了判断 相似文献
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13C NMR chemical shift assignments were obtained for the Diels-Alder adduct of phencyclone with norbornadiene in CD2Cl2 and in CDCl3 solution. The 13C spectrum at 50.3 MHz, as well as the 1H spectrum at 200.1 MHz, show evidence for hindered rotation of the two unsubstituted bridgehead phenyl rings of the adduct at ambient temperatures. In CD2Cl2 solution, all 19 of the unique 13C nuclei of this molecule give rise to individual 13C resonances. The 1H assignments which were made earlier, together with one-bond and long-range 2D heteronuclear correlation experiments, allowed the assignment of all 13C chemical shifts in the molecule. 相似文献
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滇黄精中两个呋甾皂苷的NMR研究 总被引:1,自引:0,他引:1
从滇黄精新鲜根茎中分离得到一对立体异构的呋甾皂苷, 利用1D、2D NMR鉴定其结构为: 26-O-β-D-吡喃葡萄糖基25(S)-呋甾-△5(6)-烯-3β, 22, 26-三羟基-12酮基-3-O-β-D-吡喃葡萄糖基(1→4)-β-D-吡喃呋糖苷(1, 25S-kingianoside D)和26-O-β-D-吡喃葡萄糖基25(R)-呋甾-△5(6)-烯-3β-, 22, 26-三羟基-12酮基-3-O-β-D-吡喃葡萄糖基(1→4)-β-D-吡喃呋糖苷(2, kingianoside D). 利用1D、2D NMR对两个呋甾皂苷25位的立体构型进行了确定, 并对其碳、氢信号进行了全归属. 相似文献
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The 1H and 13C NMR chemical shift assignments of a series of (E) - and (Z)-N,N-Dialkylacetamides [CH3C(O)NR1R2, with R1/R2=Me/Et (1), Me/n-Bu (2), Et/n-Bu (3), Et/t-Bu (4), Me/Hydrcxyethyl (5)., Et/Hydroxyethyl (6), Et/Acetylhydroxyethyl (7)] are reported. The 1H chemical shifts for the N-substituents of the amides 1–7 recorded in benzene-d6 and in chloroform-d1 are in agreement with the Hatton and Richards (ASIS) and Paulsen-Todt models, respectively. The 13C chemical shifts for the N-substituents of compounds 1–3 were compared with data of the corresponding symmetrical amides, and the results can be explained by the reciprocal steric compression effect of one N-substituent on the other. The validity of this explanation is confirmed by 13C spin-lattice relaxation time (T1) measurements. 相似文献
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Krzysztof R. Idzik Tobias Licha Vladimír Lukeš Peter Rapta Jaroslaw Frydel Mario Schaffer Eric Taeuscher Rainer Beckert Lothar Dunsch 《Journal of fluorescence》2014,24(1):153-160
A series of various thienyl derivatives of pyrene were synthesized by Stille cross-coupling procedure. Their structures were characterized by 1H NMR, 13C NMR and elemental analysis. The spectroscopic characteristics were investigated by UV–vis absorption and fluorescence spectra. Based on quantum chemical calculations, the energy levels of investigated molecules with respect to the pyrene molecule were also discussed. 相似文献