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Suitably functionalized alkylphenylsulfones have been used as building blocks for the synthesis of several modified side-chains steroids1. We describe here the synthesis of (S)-2-methyl and (2S)-2,3-dimethyl butyl phenylsulfones (4a) and (6), which can be used for the construction of the side chain of a few marine sterols2 or brassinosteroids3 as well. 相似文献
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Yi Bo ZHOU Jun An MA Li Xin WANG Qi Lin ZHOU* State Key Laboratoratory Institute of Elemento-Organic Chemistry Nankai University Tianjin 《中国化学快报》2002,13(10)
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… 相似文献
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以高藜芦胺为起始原料,经N-磺酰化反应制得高藜芦磺酰胺(2);2分别与芳乙烯甲醚经对甲苯磺酸催化的Pictet-Spengler反应后用金属钠脱除Ts基团合成了(±)-norlaudanosine(5a)和(±)-O,O-dimethylcoclaurine(5b);使用半量拆分法,以N-乙酰-L-苯丙氨酸为拆分剂,制得(S)-(-)-5a和(S)-(-)-5b,其结构经1H NMR,13C NMR,IR,MS和HR-ESI-MS确证。 相似文献
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苄氧乙基环氧乙烷;不对称合成;由(S)-和( R )-天冬氨酸合成( R )-和(S)-(2-苄氧乙基)环氧乙烷的改良方法 相似文献
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《合成通讯》2013,43(22):3913-3917
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. 相似文献
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Hong Zhu MA Bo WANG* Qi Zhen SHI Department of Chemistry Northwest University ShaanXi Key Laboratory of Physico-Inorganic Chemistry Xi抋n 《中国化学快报》2002,13(6)
a-Arylpropionic acids are an important class of non-steroidal anti-inflammatory agents1,2. The therapeutic efficacy of this class of drugs is well demonstrated by the introduction and extensive use of more than a dozen compounds exemplified by ibuprofen, naproxen, ketoprofen and flurbiprofen etc. However, in recent years the use of enantiomerical pure drugs in chemotherapy is becoming almost mandatory for enhancing specificity of drug action and reducing the toxicity. This awareness led to … 相似文献
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《Tetrahedron: Asymmetry》2000,11(22):4537-4541
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. 相似文献
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(S)-2-乙氧基-3-(4-羟基苯基)丙酸乙酯的合成;二乙氧基乙酸乙酯;Horner Wadswordth Emmons反应;催化氢化;化学拆分;(S) 乙氧基(羟基苯基) 相似文献
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《Tetrahedron: Asymmetry》2000,11(23):4681-4686
A short and efficient synthesis of the title compounds is described. (S)-(−)-β-Cuparenone was prepared in 31% yield from p-tolualdehyde and mesityl oxide in eight steps. Absolute stereochemistry was established by means of a diastereoselective cyclopropanation using (R,R)-hydrobenzoin as a recoverable auxiliary. 相似文献
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Dr. Alain Carpy Jean -Michel Léger Danielle Roche Michel P. Madesclaire Pascale Besse Henri Veschambre 《Structural chemistry》1995,6(3):191-195
The X-ray crystal structures of (–)-syn-4-phenyl-3-bromo-2-butyl camphanate (I) and (+-anti-4-phenyl-3-bromo-2-butyl camphanate (II) have been determined. Thesyn diastereoisomer of bromohydrin has the (2S,3S) absolute configuration whereas theanti diastereoisomer has the (2S,3R) absolute configuration. The crystallized derivatives I and II have been obtained by the reaction of each stereoisomer of bromohydrin, synthesized by reduction with baker's yeast, with (1S)-camphanic chloride. Crystal data: (I) C20H25BrO4:M
w: 409.32; orthorhombic,P212121;a=11.245(3),b=12.086(1),c=14.512(4) å; Z=4; finalR=0.053 for 1819 observed reflections. (II) C20H25BrO4;M
w=409.32; monoclinic, P21;a=11.352(1),b=6.378(1),c=14.255(2) å,=110.38(1);Z=2; finalR=0.045 for 1672 observed reflections. 相似文献
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《Journal of Coordination Chemistry》2012,65(5):911-922
Condensation of salicyldehyde with (R or S)-2-amino-2-phenylethanol or rac-2-amino-1-phenylethanol gives enantiopure (R or S)-2-(salicylaldimine)-2-phenylethanol (R- or S-H2L1) or (rac)-2-(salicylaldimine)-1-phenylethanol (rac-H2L2). The Schiff bases coordinate to [Rh(η 4-cod)(μ-O2CCH3)]2 to afford mononuclear [Rh(η 4-cod){(R or S)-2-(salicylaldiminato)-2-phenylethanol-κ 2 N,O}], [Rh(η 4-cod)(R- or S-HL1)] (1 or 2), or [Rh(η 4-cod){(rac)-2-(salicylaldiminato)-1-phenylethanol-κ 2 N,O}], [Rh(η 4-cod)(rac-HL2)] (3). The Schiff base and complexes are characterized by IR-, UV/Vis-, 1H/13C-NMR-, mass-spectroscopy, circular dichroism (CD), and polarimetry. The synthetic and spectroscopic results suggest that deprotonated Schiff base coordinates to [Rh(η 4-cod)] as a six-membered N,O-chelate with distorted square planar geometry at rhodium. CD and polarimetry measurements show the enantiopurity of the Schiff bases as well as the complexes in solution. The in situ system composed of [Rh(η 4-cod)Cl]2 and S-H2L1 has been used as a catalyst for the reduction of acetophenone into rac-1-phenylethanol with 85% conversion in diphenylsilane at 0–5°C. 相似文献
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《Tetrahedron: Asymmetry》2000,11(15):3063-3068
A convergent synthesis of (S)-(−)-3-(2-carboxy-4-pyrrolyl)-alanine (CPA) 1, a non-proteinogenic amino acid is described starting from a commercially available dimethyl l-aspartate 2 in good overall yield. 相似文献