共查询到20条相似文献,搜索用时 78 毫秒
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价廉易得的L-亮氨酸先以苄基同时保护氨基及羧基得(S)-2-(二苄胺基)-4-甲基戊酸苄酯,进而在碱性条件下与乙腈发生亲核取代反应得(S)-4-(二苄胺基)-6-甲基-3-氧代庚腈,再经硼氢化钠选择性还原羰基得(3S,4S)-4-(二苄胺基)-3-羟基-6-甲基庚腈,用双氧水氧化得(3S,4S)-4-(二苄胺基)-3-羟基-6-甲基庚酸,最后在Pd(OH)2/C-H2作用下脱掉苄基得到(3S,4S)-4-氨基-3-羟基-6-甲基庚酸,即(3S,4S)-statine。整个合成路线总产率为33.6%。 相似文献
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以2-溴丙酸和N-叔丁氧羰基-O-苄基-L-丝氨酸为起始试剂首先制得N-(2-溴丙基)-O-苄基-L-丝氨酸(BPBS), 在N,N-二甲基甲酰胺(DMF)/三乙胺(Et3N)溶剂中80 ℃经9 h后BPBS发生分子内环化反应生成(3S,6S)-3-苄氧甲基-6-甲 基-吗啉-2,5-二酮[(3S,6S)-BMMD]及(3S,6R)-BMMD共存体, 产率70%. 将所制得的共存体以乙酸乙酯为重结晶溶剂, 采用微分重结晶法, 经4次“溶解-部分重结晶”操作循环制得两种纯光学构型的(3S,6S)-BMMD和(3S,6R)-BMMD. 将两种光学纯双手性中心的BMMD分别溶于乙酸乙酯, 室温下培养得(3S,6S)-BMMD和(3S,6R)-BMMD的单晶体, 以X射线衍射法测定上述两种BMMD的分子结构. 相似文献
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以L-谷氨酸和苯甲醛为起始原料,经7步反应合成了重要中间体(2S,5R)-1-苄基-5-(2-羟乙基)吡咯烷-2-羧酸叔丁酯(1),总产率19%;1经TBDMSCl保护羟基后,用10%Pd/C催化氢解去除苄基制得游离胺(2S,5R)-5-(2-二甲基叔丁基硅氧烷基乙基)吡咯烷-2-羧酸叔丁酯(3);3与Boc-β-Cl-ala,在碱性条件下偶合得氯代烃消去产物(2S,5R)-1-[(2-叔丁氧甲酰胺基)丙烯酰基]-5-(2-二甲基叔丁基硅氧烷基乙基)吡咯烷-2-羧酸叔丁酯(4),或在中性条件下偶合得(2S,5R)-1-[(R)-2-叔丁氧甲酰胺基-3-氯丙酰基]-5-(2-二甲基叔丁基硅氧烷基乙基)吡咯烷-2-羧酸叔丁酯(5);4或5经四丁基氟化铵去除TBDMS保护并发生关环反应合成了新型的七元醚环化合物(4R,7S,9R)-4-甲基-4-叔丁氧甲酰胺基-5-羰基-3-氧杂氮杂卓[1,4]并吡咯[1,2-d]-7-羧基叔丁酯(简称6);6于室温在氯仿中静置2 d~3 d自发转换为其构象异构体(4S,7S,9R)-6(简称6’,6/6’=1/9),其结构经1H NMR,13C NMR,2D NMR和HR-ESI-MS表征。 相似文献
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以邻硝基苯甲醛为起始原料,经还原和氨基保护合成2-乙酰胺基苯甲醛(1)。应用环境友好的聚乙二醇-400为溶剂,以N-卤代丁二酰亚胺为卤代试剂对化合物2-乙酰胺基苯甲醛(1)进行卤代,制备了5-溴(氯)-2-乙酰胺基苯甲醛(2a,2b)。在三甲基氯硅烷(TMSCl)催化作用下,5-溴(氯)-2-乙酰胺基苯甲醛(2a,2b)与4-氯乙酰乙酸乙酯发生Friedlnder缩合反应,合成目标产物6-溴(氯)-2-氯甲基-3-喹啉甲酸乙酯(3a,3b)。其中2a,2b,3a,3b的结构经IR、1H NMR、13C NMR、MS得以确定。 相似文献
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A preparation of (S)-3-(phenylmethyl)morpholine from (S)-phenylalanol is described. 相似文献
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Gard Gjessing Lars-Inge Gammelster Johnsen Simen Gjelseth Antonsen Jens M. J. Nolse Yngve Stenstrm Trond Vidar Hansen 《Molecules (Basel, Switzerland)》2022,27(7)
Monohydroxylated polyunsaturated fatty acids belonging to the oxylipin class of natural products are present in marine and terrestrial sources as well as in the human body. Due to their biological activities and role in diverse biosynthetic pathways, oxylipins biosynthesized from eicosapentaenoic acid and arachidonic acid have attracted great interest from the scientific community. One example is 3-hydroxyeicosapentaenoic acid where the absolute configuration at C-3 has only been tentatively assigned. In this paper, studies on acetate type aldol reactions that enabled the preparation of 3-(R)-hydroxyeicosapentaenoic acid (3R-HETE, 2) and its enantiomer are presented. 相似文献
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The fluorinated amino acid, (2S,3S)-3'-fluoroisoleucine 3, has been synthesised by a route involving stereoselective cuprate or photochemical addition to the compound 4, derived in turn from (2S)-pyroglutamic acid. This provides a reporter group for the hydrophobic amino acid (2S)-isoleucine for use in protein studies. 相似文献
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Lall MS Hoge G Tran TP Kissel W Murphy ST Taylor C Hutchings K Samas B Ellsworth EL Curran T Showalter HD 《The Journal of organic chemistry》2012,77(10):4732-4739
(S)-3-(methylamino)-3-((R)-pyrrolidin-3-yl)propanenitrile (1) is a key intermediate in the preparation of PF-00951966, (1) a fluoroquinolone antibiotic for use against key pathogens causing community-acquired respiratory tract infections including multidrug resistant (MDR) organisms. The current work describes the development of a highly efficient and stereoselective synthesis of 1 in 10 steps with an overall yield of 24% from readily available benzyloxyacetyl chloride. Two key transformations in the synthetic sequence involve (a) catalytic asymmetric hydrogenation with chiral DM-SEGPHOS-Ru(II) complex to afford β-hydroxy amide 11b in good yield (73%) and high stereoselectivity (de 98%, ee >99%) after recrystallization and (b) S(N)2 substitution reaction with methylamine to provide diamine 14 with inversion of configuration at the 1'-position in high yield (80%), after efficient purification using a simple acid/base extraction protocol. 相似文献
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Optically active (+)-(S)-5-sec-butyl- and (-)-(S)-3-sec-butyl-2(1H)-pyridinone are synthesized and the relationship between optical activity and minimum optical purity of the latter is determined. 相似文献