Synthesis of analogues of GABA. XII. cis- and trans-4-Aminotetrahydrofuran-2-carboxylic acid

1984 ◽  
Vol 37 (5) ◽  
pp. 1123 ◽  
Author(s):  
RD Allan ◽  
HW Tran
Keyword(s):  
Carboxylic Acid ◽  
Conformationally Restricted ◽  
Cis And Trans ◽  
Cis Isomer

cis- and trans-4-Aminotetrahydrofuran-2-carboxylic acid have been synthesized as conformationally restricted analogues of GABA and their stereochemistry confirmed by the cyclization of the cis isomer to the bicyclic N-tosyl lactam.

Structure et réactivité. V. Étude par résonance magnétique nucléaire des produits d'halogénation des tert-butyl-3 methoxycarbonyl-4 cyclohexènes

1983 ◽  
Vol 61 (2) ◽  
pp. 362-365 ◽  
Author(s):  
Jeanine Bouteiller-Prati ◽  
Jean-Claude Bouteiller ◽  
Jean-Pierre Aycard
Keyword(s):  
Carboxylic Acid ◽  
Trans Isomer ◽  
Chlorination Reaction ◽  
Stable Isomer ◽  
Tert Butyl ◽  
Twist Conformation ◽  
Résonance Magnétique ◽  
Acid Lactone ◽  
Cis And Trans ◽  
Cis Isomer

The product of the bromination (chlorination) reaction on cis and trans 3-tert-butyl 4-carbomethoxy cyclohexene is studied by nmr. The results show that the reaction of the cis isomer gives 90% of the trans 4-bromo (chloro) cis 3-hydroxy trans 2-tert-butyl cyclohexane 1-carboxylic acid lactone and the reaction of the trans isomer gives trans 1,2-dibromo (dichloro) cis 3-tert-butyl trans 4-carbomethoxy cyclohexane which adopts a twist conformation. For the dibromo compound this kinetic product gives the corresponding thermodynamically more stable isomer, trans 1,2-dibromo trans 3-tert-butyl cis 4-carbomethoxy cyclohexane, by a diotropic rearrangement. The formation of the kinetic product is explained by the reaction of the less stable diaxial conformer of the cyclohexene derivative.

scholarly journals Increases in plasma trans-EETs and blood pressure reduction in spontaneously hypertensive rats

2011 ◽  
Vol 300 (6) ◽  
pp. H1990-H1996 ◽  
Author(s):  
Houli Jiang ◽  
John Quilley ◽  
Anabel B. Doumad ◽  
Angela G. Zhu ◽  
John R. Falck ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Spontaneously Hypertensive Rat ◽  
Blood Pressure Reduction ◽  
Maximal Velocity ◽  
Spontaneously Hypertensive ◽  
Cis And Trans Isomers ◽  
Wistar Kyoto Rat ◽  
Wistar Kyoto ◽  
Cis And Trans ◽  
Cis Isomer

Epoxyeicosatrienoic acids (EETs) are vasodilator, natriuretic, and antiinflammatory lipid mediators. Both cis- and trans-EETs are stored in phospholipids and in red blood cells (RBCs) in the circulation; the maximal velocity ( Vmax) of trans-EET hydrolysis by soluble epoxide hydrolase (sEH) is threefold that of cis-EETs. Because RBCs of the spontaneously hypertensive rat (SHR) exhibit increased sEH activity, a deficiency of trans-EETs in the SHR was hypothesized to increase blood pressure (BP). This prediction was fulfilled, since sEH inhibition with cis-4-[4-(3-adamantan-1-ylureido)cyclohexyloxy]benzoic acid (AUCB; 2 mg·kg−1·day−1 for 7 days) in the SHR reduced mean BP from 176 ± 8 to 153 ± 5 mmHg ( P < 0.05), whereas BP in the control Wistar-Kyoto rat (WKY) was unaffected. Plasma levels of EETs in the SHR were lower than in the age-matched control WKY (16.4 ± 1.6 vs. 26.1 ± 1.8 ng/ml; P < 0.05). The decrease in BP in the SHR treated with AUCB was associated with an increase in plasma EETs, which was mostly accounted for by increasing trans-EET from 4.1 ± 0.2 to 7.9 ± 1.5 ng/ml ( P < 0.05). Consistent with the effect of increased plasma trans-EETs and reduced BP in the SHR, the 14,15- trans-EET was more potent (ED50 10−10 M; maximum dilation 59 ± 15 μm) than the cis-isomer (ED50 10−9 M; maximum dilation 30 ± 11 μm) in relaxing rat preconstricted arcuate arteries. The 11,12-EET cis- and trans-isomers were equipotent dilators as were the 8,9-EET isomers. In summary, inhibition of sEH resulted in a twofold increase in plasma trans-EETs and reduced mean BP in the SHR. The greater vasodilator potency of trans- vs. cis-EETs may contribute to the antihypertensive effects of sEH inhibitors.

scholarly journals Reaction of cis- and trans-Dichlorotetra(Dimethylsulfoxide)Ruthenium(II) With the Antiviral Drug Acyclovir

2000 ◽  
Vol 7 (6) ◽  
pp. 325-334 ◽  
Author(s):  
Aglaia Koutsodimou ◽  
Giovanni Natile
Keyword(s):  
Trans Isomer ◽  
Early Stage ◽  
Antiviral Drug ◽  
Metallic Substrate ◽  
Purine Base ◽  
Coordination Environment ◽  
Molar Ratios ◽  
Discrete Amount ◽  
Cis And Trans ◽  
Cis Isomer

NMR was used to investigate the reaction of cis- and trans-[RuCl2(DMSO)4] with the antiviral drug acyclovir, a guanine derivative containing the acyclic (2-hydroxo) ethoxymethyl pendant linked to N(9). Studies were performed in aqueous solutions at ambient temperature and at 37 °C, and at various molar ratios. Both isomers yielded two compounds, a monoadduct and a bisadduct, the relative yields being dependent upon the metal to ligand concentration ratios. The products derived from the two Ru isomers displayed identical NMR spectra, suggesting that they have the same coordination environment, however the rate of formation of the monoadduct was higher in the case of the trans isomer than in the case of the cis isomer, while the rate of conversion of the monoadduct into the bisadduct appeared to be similar in both cases. As a consequence in the case of the trans isomer there is accumulation of monoadduct in the early stage of the reaction, whose concentration afterwards decreases with the progress of the reaction. As for platinum, also for ruthenium the preferred binding site is N(7) of the purine base, however, in the case of ruthenium a discrete amount of bisadduct is formed even in the presence of an excess of metallic substrate with respect to the acyclovir ligand; under similar conditions a platinum substrate would have given, nearly exclusively, the monoadduct.

scholarly journals Vibrational circular dichroism as a probe of solid‐state organisation of derivatives of cyclic β‐amino acids: Cis ‐ and trans ‐2‐aminocyclobutane‐1‐carboxylic acid

Chirality ◽  
2019 ◽  
Vol 31 (8) ◽  
pp. 547-560 ◽  
Author(s):  
Valérie Declerck ◽  
Ariel Pérez‐Mellor ◽  
Régis Guillot ◽  
David J. Aitken ◽  
Michel Mons ◽  
...  
Keyword(s):  
Amino Acids ◽  
Circular Dichroism ◽  
Solid State ◽  
Carboxylic Acid ◽  
Vibrational Circular Dichroism ◽  
Cis And Trans ◽  
Derivatives Of ◽  
Circular Dichroïsm

[1H,15N] N.M.R. Kinetic Studies of Reactions of cis- and trans-[PtCl2(15NH3)(c-C6H1115NH2)] with Guanosine 5'-Monophosphate

1999 ◽  
Vol 52 (3) ◽  
pp. 173 ◽  
Author(s):  
Sarah J. Barton ◽  
Kevin J. Barnham ◽  
Abraha Habtemariam ◽  
Urban Frey ◽  
Rodney E. Sue ◽  
...  
Keyword(s):  
Trans Isomer ◽  
Active Metabolite ◽  
Kinetic Studies ◽  
Trans Influence ◽  
Trans Complex ◽  
Kinetics Of Reaction ◽  
Cis And Trans ◽  
Kinetics Of ◽  
Cis Isomer ◽  
Amine Ligand

cis-[PtCl2(15NH3)(c-C6H11NH2)] is an active metabolite of the oral platinum(IV) anticancer drug cis,trans,cis-[PtCl2(CH3CO2)2(NH2)(c-C6H11NH2)]. Since it is likely that guanine bases on DNA are targets for this drug, we have analysed the kinetics of reaction of this platinum(II) metabolite with guanosine 5′-monophosphate (5′-GMP) at 310 K, pH 7, using [1H, 15N] n.m.r. methods. Reactions of the trans isomer are reported for comparison. The reactions proceed via aquated intermediates, and, for the cis isomer, the rates of aquation and substitution of H2O by 5′-GMP are 2-5 times faster trans to the amine ligand (c-C6H11NH2) compared to trans to NH3 for both the first and second steps. For the trans complex, the first aquation step is c. 3 times faster than for the cis complex, as expected from the higher trans influence of Cl¯, whereas the rate of the second aquation step (trans to N7 of 5′-GMP) is comparable to that trans to NH3. These findings have implications for the courses of reactions with DNA.

Iron Carbonyl Complexes of the Diastereomers of cis-(C6H5)(CH3)AsC(CF3)=C(CF3)As(CH3)(C6H5)

1973 ◽  
Vol 51 (6) ◽  
pp. 936-941 ◽  
Author(s):  
W. R. Cullen ◽  
L. Mihichuk
Keyword(s):  
Iron Carbonyl ◽  
Geometric Isomers ◽  
Carbonyl Complexes ◽  
Cis And Trans ◽  
Cis Isomer

The reaction of CF3≡CCF3 with (C6H5)(CH3)As—As(CH3)(C6H5) gave both cis- and trans-(C6H5)(CH3)AsC(CF3)=C(CF3)As(CH3)(C6H5), (L—L), in nearly equal amounts. When hexafluoroacetone is used as solvent the cis-isomer predominates (88%). The two diastereomers of the cis-adduct were isolated and reacted with Fe(CO)5 to afford (L—L)Fe(CO)3 and (L—L)Fe2(CO)6. Two of the three possible geometric isomers of the latter were obtained and their properties allowed assignment of the configuration of the starting ligands. Minor amounts of the symmetric and asymmetric forms of [Fe(CO)3As(CH3)(C6H5)]2 were also obtained through loss of fluorocarbon.

Sur la réduction de polyméthyldihydro-2,3 phénalènones-1 par l'hydrure de lithium et d'aluminium

1974 ◽  
Vol 52 (17) ◽  
pp. 3106-3112 ◽  
Author(s):  
E. Costakis ◽  
P. Canonne ◽  
R. St-Jean
Keyword(s):  
Trans Isomer ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Considerable Extent ◽  
Lithium Aluminum ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Cis And Trans ◽  
Cis Isomer ◽  
Steric Constraints

The reduction of some polymethyl-2,3-dihydro phenalen-1-ones by lithium aluminum hydride yields a mixture of cis and trans isomers; the percentage of each isomer depends to a considerable extent on its structure. Indeed, for some, the trans isomer predominates while for others the cis isomer is obtained in up to 88% yields. Moreover, in the particular case in which the trans isomer is formed in low yields, its preferred conformation is trans diaxial.The steric constraints which render certain transition states unfavourable during the attack of the hydride are discussed with the aid of spectroscopic data on the alcohols obtained. [Journal translation]

Dimerization in trans-4-butyl-cyclohexane carboxylic acid and in its mixture with 12% cis-isomer observed via 1H- and 2H-NMR

1998 ◽  
Author(s):  
Sofia I. Torgova ◽  
D. Abramic ◽  
Alfredo Strigazzi ◽  
Slobodan Zumer
Keyword(s):  
Carboxylic Acid ◽  
H Nmr ◽  
In Trans ◽  
Cyclohexane Carboxylic Acid ◽  
Cis Isomer
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