An efficient one-pot three-component procedure for the synthesis of new chiral spiro-oxindolopyrrolizidines with highly regio-, diastereo-, and enantioselective from 1,3-dipolar cycloaddition of azomethine ylides and optically pure active cinamoyl oxazolidinone are described. The process occurs at room temperature in aqueous ethanol as green solvent and in the absence of any bidentate chelating...

In this paper, the propagation of electromagnetic waves through an infinite slab of uni- or bi- axial chiral medium is analytically formulated for an arbitrary incidence using 4×4 matrix method. In this powerful method, a state vector differential equation is extracted whose solution is given in terms of a transition matrix relating the tangential components of electric and magnetic fields at t...

due to high resolution power of sulfated cyclodextrins (hs-cds), utilization of these selectors for chiral resolution of 7 basic and 2 zwitterionic drugs have been examined. experiments were performed on a hp3dce instrument equipped with an on-column diode array uv absorbance detector. fused silica capillaries with an inner diameter of 50 ?m, an outer diameter of 365 ?m, and a total length of 4...

chiral pyrrolidines and pyrrolizidines with spirooxindole ring systems are the central skeletons for numerous alkaloids and pharmacologically important compounds. gelesmine, pseudotabersonine, formosanine, isoformosanine, morroniside and mitraphylline are some of the alkaloids containing spirooxindole ring systems. derivatives of spirooxindole find very wide biological applications as anti micr...

the distribution behavior of ofloxacin enantiomers was examined in the aqueous and organic solvent of a two-phase system containing chiral selector l-tartarate. the effect of extraction equilibrium time, buffer ph, organic solvents and length of alkyl chain of l-tartarate on the partition coefficients and enantioselectivity of racemic ofloxacin were investigated, respectively. the l-tartarate f...

The title compound, C(18)H(18)N(3)O(+)·PF(6) (-), is a chiral bicyclic 1,2,4-triazolium salt which contains four rings, viz. a triazolium, a morpholine and two phenyl rings. Analysis of bond lengths shows that the N-CH-N group in the triazolium ring conforms to a typical three-center/four-electron bond (also known as the Pimentel-Rundle three-center model). The structure is completed by a disor...

Vitamin E is recognized as an essential vitamin since its discovery in 1922. Most vegetable oils contain a mixture of tocopherols and tocotrienols in the vitamin E composition. Structurally, tocopherols and tocotrienols share a similar chromanol ring and a side chain at the C-2 position. Owing to the three chiral centers in tocopherols, they can appear as eight different stereoisomers. Plant so...

“In 1952 we published ‘The Rule of “Steric Control of Asymmetric Induction” in the Syntheses of Acylic Systems.’ This hypothesis resulted from our syntheses of organic chemical systems needed to investigate our newly discovered ‘phenonium ion.’ Our rule evolved from earlier observations of the Frenchman, M. Tiffeneau, and the Scot, A. McKenzie. These early 20th century investigators observed a ...

The amide moiety of peptides can be replaced for example by a triazole moiety, which is considered to be bioisosteric. Therefore, the carbonyl moiety of an amino acid has to be replaced by an alkyne in order to provide a precursor of such peptidomimetics. As most amino acids have a chiral center at Cα, such amide bond surrogates need a chiral moiety. Here the asymmetric synthesis of a set of 24...

Two amino acid-based (leucine and isoleucine) alkenoxy micelle polymers were employed in this study for the separation of multichiral center-bearing beta-blockers, nadolol and labetalol. These polymers include polysodium N-undecenoxy carbonyl-L-leucinate (poly-L-SUCL) and polysodium N-undecenoxy carbonyl-L-isoleucinate (poly-L-SUCIL). Detailed synthesis and characterization were reported in our...