SYNTHESIS,CRYSTAL STRUCTURE AND DFT STUDY OF NOVEL (2S,2′S,6R,6′R)-4,4′-(6-BROMOPYRIDO[2,3-d]PYRIMIDINE-2,4-DIYL)BIS(2,6-DIMETHYLMORPHOLINE)

Journal of Structural Chemistry - (2S,2′S,6R,6′R)-4,4′-(6-Bromopyrido[2,3-d]pyrimidine-2,4-diyl)bis(2,6-dimethylmorpholine) is a novel organic intermediate having...     

Synthesis and Structure Determination of (2S, 2′S)-3-Phenyl-2-(pyrrolidin-2′-yl)- propionic Acid

Abstract

Aβ²,β³-homoproline derivative, (2S, 2′S)-3-phenyl-2-(pyrrolidin-2′-yl)propionic acid, was synthesized starting from l-proline. After preparation of the (4S, 4aS)-4-benzyl-4a,5,6,7-tetrahydro-pyrrolo-[1,2-c]pyrimidine-1,3-dione under a mild condition, the absolute configuration of target compound was assigned using 2D H-H COSY and H-H NOESY technologies.     

An efficient and stereoselective synthesis of (2S,1′S,2′S)-2-(carboxycyclopropyl) glycine (LCCG-I): conformationally constrained l-glutamate analogues

Conformationally restricted metabotropic glutamate receptor agonist (2S,1′S,2′S)-2-(Carboxycyclopropyl) glycine (LCCG-I) 1 have been efficiently synthesized in a stereoselective manner. A convenient five step synthesis of 1 from readily available (−)-dimenthyl (1S,2S)-cyclopropane-1,2-dicarboxylate 5 in 49% overall yield is described.     

手性5-(R)-(1′R,2′S,5′R)-孟氧基丁内酯并[3,4-b]-2(S)-6(R)-1-N-环己基氮杂环丙烷的合成及晶体结构

环己胺与手性元5-(R)-(1′R,2′S,5′R)-孟氧基-3-溴-2(5H)-呋喃酮的不对称M ichael加成/分子内亲核取代反应,得到含有两个新手性中心的氮杂环丙烷/稠合丁内酯标题化合物。对其进行了谱学表征和X-射线单晶衍射测定。标题化合物分子式为C20H33NO3,M r=335.47,三斜晶系,P1空间群,晶胞参数:a=5.438(11)。A,b=8.117(2)。A,c=11.572(2)。A,α=96.84(3)°,β=94.48(3)°,γ=101.86(3),°V=493.5(2)。A3,Z=1,D c=1.129g/cm3,R=0.0867,wR=0.2344。     

2-{(4a′S,6a′S,10a′R,10b′R)-Octahydrospiro[1,3-dioxolane-2,2′-pyrano[2,3-c]chromen]-6a′(1′H)-yloxy}ethanol in the Synthesis of (2S)- and (2R)-Dodecane-1,2-diols

Russian Journal of Organic Chemistry - Michael adduct of levoglucosenone and cyclohexanone, 1,6-anhydro-3,4-dideoxy-4-C-(2-oxocyclohexan-1-yl)-β-D-erythrohexo-2-ulose, was treated with...     

Asymmetric Synthesis of (-)-(2R,3R,6S)-Irnigaine

Introduction　　Asarelativelynewmemberofnaturalalkaloidswith2 ,6 disubstituted 3 piperidinolskeleton ,irnigaine 1wasisolatedfromthetubersofArisarumVulgare (Araceae)in1995byMelhaouiandBode .1Itsstructureandrelativeconfigurationswereelucidatedby1HNMRstudiesandtheabsoluteconfigurationwasproposedonthebasisofitsopti calrotation .1Soonafterthen ,Meyerandhisco workersreportedthefirstsynthesisof (- ) (2R ,3R ,6S) irni gaineandtheconfigurationconfirmation .Althoughtheirsynthesisroutewasshortan…     

Synthesis and biological activity of the (−)-(2R,3S,4S)-3-azido-4-methoxy-2-(1′S-methoxy-2′-azido)ethyl-thiolane

A stereospecific ring contraction reaction, promoted by NaN₃, was detected starting from a thiepane derivative obtained from d-sorbitol, an inexpensive alcohol sugar. The major polyfunctionalized thiolane derivative obtained was investigated as a potential glycosidase inhibitor.     

Enantioselective synthesis of (2S,2′R)-erythro-methylphenidate

A new approach towards the enantioselective synthesis of (2S,2′R)-erythro-methylphenidate (1) is described. The key step in the synthesis utilizes Evans' 4-substituted-2-oxazolidinone chiral auxiliary to control the diastereofacial selectivity in the hydrogenation of enamine intermediate 6, yielding the hydrogenated product 7 with excellent diastereoselectivity. Methanolysis of 7 afforded 1 with excellent enantiopurity.     

6，6′-二硝基-2，2′-联苯酸铀(Ⅵ)配聚物

Uranium(Ⅵ) complex {[UO₂((R，S)-1，1′-biphenyl-6，6′-dinitro-2，2′-dicarboxylate)(H₂O)](H₂O)} was obtained by the hydrothermal treatment of UO₂(NO₃)₂·6H₂O with (R，S)-6，6′-dinitro-biphenyl-2，2′-dicarboxylic acid(BSNCA) (L) in water at 180 ℃ in Pyrex tube. The crystal belongs to triclinic system， space group P1， with a=0.903 45(14) nm， b=1.024 43(16) nm， c=1.058 95(16) nm， α=90.411(3)°， β=112.934(3)°， γ=92.554(3)°. CCDC: 659613.     

Synthesis of (−)-(1′S,4aS,8aR)- and (+)-(1′S,4aR,8aS)-4a-ethyl-1-(1′-phenylethyl)-octahydroquinolin-7-ones

A synthesis of the enamine (−)-(1′S)-5-ethyl-1-(1′-phenylethyl)-1,2,3,4-tetrahydropyridine 4 and its application in a synthesis of (−)-(1′S,4aS,8aR)- and (+)-(1′S,4aR,8aS)-4a-ethyl-1-(1′-phenylethyl)-octahydroquinolin-7-ones 5 and 6 is described. In addition, an X-ray study of 6 is reported. Finally, the preparation of (+)-(4aS,8aR)-4a-ethyl-octahydroquinolin-7-one 7 is described.     

(1′S,4R,5R)-2-(1′-溴乙基)-2-(5-溴-6-甲氧基-2-萘基)-1,3-二氧戊环-4,5-二羧酸的不对称合成

萘普生［（Ｓ）２（６甲氧基２萘基）丙酸］是一种非常重要的非麻醉性消炎镇痛药．周宏英等［１］报道了用手性膦配体ＤＤＰＰＩ对２（６甲氧基２萘基）乙醇进行不对称羰基化反应合成了萘普生甲酯．本文用（２Ｒ,３Ｒ）酒石酸二甲酯为手性辅助剂,以...     

Synthesis of 5-substituted-3-[(2′S,3′S)-3′-hydroxy-2′-hydroxymethyltetrahydrofuran-3′-yl]-1,2,4-oxadiazoles and their epimers

5-Phenyl-3-[(2′R,3′S)-3′-hydroxy-2′-dimethoxymethyltetrahydrofuran-3′-yl]-1,2,4-oxadiazole 10a and its epimer 11a, 5-methyl-3-[(2′R,3′S)-3′-hydroxy-2′-dimethoxymethyltetrahydrofuran-3′-yl]-1,2,4-oxadiazole 10b and its epimer 11b were synthesized from cyanohydrin benzoates 8a, 9a and cyanohydrin acetates 8b, 9b, respectively, by treatment with hydroxylamine in methanol via intramolecular transacylation and subsequent cyclization of the corresponding amidoximes. Hydrolysis and reduction of the dimethoxymethyl groups in the above compounds gave the desired compounds 12a, 13a, 12b and 13b.     

DiastereoselectiveandEnantioselectiveSynthesisof(1S,2S)-2-Ethyl-1-aminocyclopropaneCarboxylicAcid

During the last decade, 1-aminocyclopropanecarboxylic acid and its derivatives (ACCS) have attracted increasing attention of organic and bioorganic chemists due to their outstanding biological properties, ranging from antimicrobial, insecticidal, plant growth and fruit ripening controls, etc.1. Moreover, the three-membered carbocycle provides building blocks of unprecedented synthetic potential because it undergoes selective ring opening, ring enlargement or cycloaddition reactions2. The mo…     

棒丝氨酸的全合成研究 Ⅰ.从D-葡萄糖合成3-[(3′R,5′S)-7′-氧代-1′-氮杂-4′-氧杂双环[3.2.0]-庚-3′-基]-3-O-苄基-(2S,3S)-丝氨酸及其(3′R,5′R)-差向异构体

以D-葡萄糖为原料经侧链氨基酸合成,与β-内酰胺缩合,嗯唑烷环合和除保护基等反应合成了棒丝氨酸的O-苄基衍生物,3-[(3′R,5′S)-7′-氧代-1-氮杂-4-氧杂双环[3.2.0]-庚-3′-基]-3-O-苄基-(2S,3S)-丝氨酸(17)及其(3′R,5′R)差向异构体(18)。     

(3S,6S)-及(3S,6R)-3-苄氧甲基-6-甲基-吗啉-2,5-二酮的 制备及其晶体结构

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.     

A Synthesis of 2-(6′-Carboxy-2′-cis-Hexenyl)-4-Hydroxycyclopent-2-EN-1-ONE,a Prostagiandin Intermediate1

Several recent publications² report the synthesis of prostaglandin E₁ (PGE₁, 2) and some of its derivatives by conjugate addition reactions to ether-ester forms of hydroxycyclopentenone acid 1.³ The simplicity of this approach makes its application to the preparation of prostaglandins of the PG₂- and PG₃ - series (cis-Δ⁵)⁴ an attractive alternative to the existing elegant methods.⁵ We now wish to report a five-step synthesis of the requisite hydroxycyclopentenone precursor 3 from the readily available⁶ lactone 4.     

微波辐射快速合成2-(2′-羟苯基)-5(6)取代苯并咪唑衍生物

苯并咪唑衍生物具有一定的抗病毒能力[1 ] ,一些苯并咪唑衍生物已用作农用抗植物病毒剂[2 ] 。一锅煮合成反应时间较长 ,产率中等[3,4] 。本文用取代邻苯二胺和水杨酸为原料 ,吡啶为溶剂 ,ＰＯＣｌ3为催化剂 ,微波辐射法合成了标题化合物。合成路线如下 :1　实验部分1 1　仪器ＷＣ 1型熔点测定仪 (温度计未校正 ) ;日本岛津ＩＲ 435红外光谱仪 (ＫＢｒ压片 ) ;ＴＥＯＬ ＦＸ90Ｑ核磁共振仪 ,ＤＭＳＯ ｄ6 为溶剂 ;日本柳公Ｃ·Ｈ·Ｎ元素分析仪ＭＴ 3;苏州三星电子有限公司产新天地Ｍ9Ｋ88型微波炉 ,输出功率 85 0Ｗ ,2 4 5 0Ｈｚ。1 2　…     

Asymmetric Hydrogenation Synthesis of (S)-(+)-2-(6′-methoxyl-2-naphthyl) propionic Acid by Cinchona Modified Pd(0)-α-FeOOH Catalyst

During the past decades enormous progress was made in asymmetric catalytic synthesis, an well-known example is BINAP1, the chiral hydrogenation synthesis of S-(+)-naproxen catalyzed by BINAP-Ru dicarboxylate complexes provides excellent enantioselectivity (up to 99% ee) and good chemical yield (92%), however the pressures is relatively high (135-150 atm) and the (S)-BINAP-Ru(III) complex is very expensive. This problem may present a practical limitation. In recent years new methodolo…     

5(6)-羧基荧光素标记2′-脱氧尿苷的合成

以5-碘-2'-脱氧尿嘧啶为起始原料, 5(6)-羧基荧光素为荧光标记物, 经6步反应合成了5(6)-羧基荧光素标记的2′-脱氧尿苷, 并利用高效液相色谱(HPLC), ¹H NMR和¹³C NMR对目标化合物的纯度和结构进行了表征.