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1 INTRODUCTION Opioid analogues still remain important drugs for the relief of severe pain and morphine is still the drug of choice in such situations. For many years, the search for new centrally acting opioid deriva- tives with pain-relieving properties and without un- desired side effects, such as addiction, obstipation, etc., has been the goal of a large number of scien- tists[1-3]. Consequently, a wide variety of modifyca- tions of the well-known alkaloids morphine, codeine and thebai… 相似文献
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The reaction of 7α-acetyl-6,14-endoethano-6,7,8,14-tetrahydrothebaine with 2-(thien-2-yl)ethylmagnesium bromide was investigated. The tertiary alcohol derivative 7α-[R-l-hydroxyl-l-methyl-3-(thien-2-yl)propyl])-6,14- endoethano-6,7,8,14-tetrahydrothebaine (3) and a by-product 4 were isolated. The structure of 4 was elucidated by X-ray analysis. The Grignard reaction shows high degree of stereoselectivity according with Cram rule. The crystal structure of 4 indicates that dihydrofuran ring was opened to form a phenolic hydroxyl group and a three-membered ring structure. It maintains the main rigid structure of morphine and contains a C(6)-C(14) enthano bridge. The 1-hydroxyl-1-methyl-3-(thien-2-yl)propyl group at C(7) position adopted S-configuration. 相似文献
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采用手性固定相高效液相色谱法研究了甲醇-磷酸盐体系、乙腈-磷酸盐体系和甲醇-乙腈-磷酸盐体系对系列抗胆碱能药物的手性拆分情况,讨论了流动相的各个因素(有机相的种类和比例、磷酸盐浓度、酸度、三乙胺用量等)对手性拆分的影响。研究表明,流动相中较大的水相比例、较高的磷酸盐浓度、pH和三乙胺浓度更有利于抗胆碱能药物的手性拆分。通过对比研究10种抗胆碱能手性药物的色谱行为,从结构上讨论了化合物中不同官能团对保留时间及手性拆分的影响,并探讨了手性拆分的内在机制。 相似文献
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A novel and simple procedure for the enantiospecific synthesis of penehyclidine hydrochloride (8018) isomers and the R configuration derivatives was described. The intramolecular asymmetric cyclization of the monosulfonate of compound 1,2-diol was applied to the execution of the synthesis of the key chiral building block for the first time. The aimed products were obtained with moderate yield in〉99% ee. 相似文献
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环二肽如L-组-L-脯环二肽、L-脯-L-羟脯环二肽等广泛存在于自然界,同时发现这些环肽显示出不同的生理活性.自然界存在的环肽中,常常包含一些非核糖体氨基酸,而这些结构往往是产生活性的重要结构单元.本研究应用脯氨酸为主要原料,在与α-烷氧亚氨苯丙酰氯反应生成N-α-烷氧亚氨苯丙酰脯氨酸后,再用氯化亚砜处理,得到对应的酰氯,E-构型肟N作为亲核试剂进攻酰氯环合得到N-烷氧基的盐,随后重排得到N-烷氧环二肽.其结构均通过IR,1H NMR,13C NMR,1H-1HNMR,MS和元素分析予以确认.研究发现,环化用有机碱如三乙胺催化时,所得环肽常常是消旋体,在没有碱存在时,得到的环肽具有旋光性.可能的原因是,前者是按烯酮机理环合的,后者是按加成-消去机理环合的. 相似文献