共查询到20条相似文献,搜索用时 15 毫秒
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Shibaeva K. O. Romanov S. R. Moryasheva A. D. Shulaeva M. P. Pozdeev O. K. Bakhtiyarova Y. V. 《Russian Journal of General Chemistry》2022,92(7):1228-1232
Russian Journal of General Chemistry - As a result of reactions of nucleophilic addition of tertiary phosphines to pulegone in the presence of hydrochloric acid, quaternary phosphonium salts were... 相似文献
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R-(+)-pulegone (1) is transformed to (R)-5-methyl-2-(phenylsulfinyl)cyclohexanone (5) (65%, 3 steps). Sulfoxide 5 is converted to R-(-)-3,5-dimethylcyclohex-2-en-1-one (4) (53%, 4 steps) and S-(+)-4 (26%, 3 steps). 相似文献
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(+)-(1S,2S,5R)-8-联苯薄荷醇的合成 总被引:4,自引:0,他引:4
以(R)-( )-pu legone为起始原料,经1,4-加成,还原两步反应合成了手性辅助试剂( )-(1S,2S,5R)-8-联苯薄荷醇及其差向异构体(-)-(1R,2S,5R)-8-联苯薄荷醇,总产率95%。其结构经1H NMR,13C NMR,IR,MS和X-射线衍射仪表征。 相似文献
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A highly enantioselective synthesis of the versatile chiral synthons possessing one stereogenic center, (S)- and (R)-4-aryl-5-hydroxy-(2E)-pentenoate (3) was achieved based on the enzymatic reaction of (+/-)-3 with commercially available lipases MY-30 or OF-360 from Candida rugosa. Application of (S)-3 and (R)-3 to the total syntheses of(S)-curcuphenol (1), (S)-curcudiol (2), and (R)-curcuphenol (1), respectively, is described. 相似文献
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Zahraa S. Al-Taie Barbara Bartholomew Christopher Cartmell Richard T. Froom Russell G. Kerr Rolf Kraehenbuehl Patrick J. Murphy Robert J. Nash Yana B. Penkova Alexander van Teijlingen 《Molecules (Basel, Switzerland)》2022,27(4)
The absolute stereochemistry of the marine alkaloid (+)-(R)-tiruchanduramine was established via a convergent total synthesis in six steps and 15.5% overall yield from Fmoc-D-Dab(Boc)-OH. 相似文献
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An asymmetric synthesis of neurokinin substance P receptor antagonist (+)-L-733,060 starting from enantiomerically pure ethyl (R)-(+)-2,3-epoxypropanoate (ethyl glycidate) is described. The synthesis relies on a diastereoselective reductive amination, regioselective intramolecular epoxide opening, and in situ cyclization as the key steps. 相似文献
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Novel Synthesis of (?)-(R)-Cembrene A, Synthesis of (+)-(R)-Cembrenene and (+)-(S)-Cembrene A novel synthesis of (?)-(R)-cembrene A ((?)- 3 ) was developed using the Sharpless epoxidation for the introduction of the chiral center. Furthermore, the synthesis of (+)-(R)-cembrenene ((+)- 4 ) showed that this cembranoid must have the (R)-configuration and not, as previously reported, the (S)-configuration. Selective hydrogenation of (+)- 4 afforded (+)-(S)-cenibrene ((+)- 5 ). 相似文献
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F. Cataldo Y. Keheyan S. Baccaro 《Journal of Radioanalytical and Nuclear Chemistry》2004,262(2):423-428
Three isomeric chiral terpenes, R(+)-limonene, S(-)-limonene and R(-)-a-phellandrene were γ-radiolyzed in sealed vials at
room temperature with a total radiation dose of 317 kGy. The radiolyzed samples were analyzed by FT-IR, electronic absorption
spectroscopy, liquid chromatography using a diode-array detector (HPLC-DAD) and by polarimetry. Despite a relatively high
radiation dose used, all the chiral molecules selected have shown a low radioracemization rate. This fact and the role played
by the impurities in the selective radio-degradation of one of the two enantiomers has been discussed in the context of the
origin of chirality in prebiotic molecules and the chirality enhancement in a prebiotic world. The results were also discussed
in the frame of the radiosterilization technique of chiral drugs, perfumes and food components.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Summary Optically pure (R)-(+)-lithium lactate (7) and its benzyl ether analogue (6a) were obtained from acetaldehyde usingEliel's 1,3-trans-oxathiane (1) as the chiral auxiliary for chromatographic separation.
Herstellung von (R)-(+)-Lithiumlactat
Zusammenfassung Optisch reines (R)-(+)-Lithiumlactat (7) und sein Benzyletheranaloges (6a) wurden mittelsEliels 1,3-trans-Oxathian (1) als chiralem Hilfsstoff zur chromatographischen Trennung aus Acetaldehyd hergestellt.相似文献
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Grant A. Boyle Thavendran Govender Hendrik G. Kruger Glenn E. M. Maguire 《Structural chemistry》2009,20(5):925-932
The complete NMR elucidation of five camphor-derived ligands is reported. 2D NMR techniques such as NOESY are used to assist
in the determination of the orientation of the donor groups in space. The compounds were synthesized as ligands to be used
in asymmetric catalysis. They represent the first instance where both donor groups are pendant on the C3 position of the camphor
skeleton. The single crystal X-ray structure of one of the ligands was obtained and was helpful in determining the potential
NOESY interactions within the molecule. For the other ligands, density functional theory (DFT) optimizations was performed
[B3LYP/6-31+g(d)] to visualize possible NOE interactions.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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A G Wee 《The Journal of organic chemistry》2001,66(25):8513-8517
(-)- and (+)-Geissman-Waiss lactone, 4b, was efficiently prepared via the intramolecular C-H insertion reaction of the chiral nonracemic diazoacetates (-)-5a and (+)-5b catalyzed by dirhodium(II) tetrakis[methyl (5R and 5S)-3-phenylpropanoyl-2-imidazolidinone-5-carboxylate]. The cyclization was found to proceed with excellent regioselectivity and cis-diastereoselectivity. The bicyclic lactone (-)-4b was successfully used in the synthesis of the necine base, (-)-turneforcidine 2. 相似文献
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《Tetrahedron: Asymmetry》1998,9(2):189-191
Enantiopure (2R,5R)-(+)-2,5-dimethylthiolane was synthesized by cyclization with sodium sulfide of the dimesylate of (2S,5S)-(+)-2,5-hexanediol, which was obtained by baker's yeast (Saccharomyces cerevisiae) reduction of acetonyl acetone in high enantiomeric purity. The structure of the diol and absolute stereochemistry of the sulfone derived from the title molecule were determined by X-ray crystal structure analysis. 相似文献
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A short and efficient synthesis of the commercially unavailable (R)-(+) isomer of perillaldehyde from (+)-limonene oxide has been developed. 相似文献