Indeed, where both cis and trans isomers are present in solution, the possibility has to be considered that the minor isomer, whether cis or trans, may be the bioactive conformation, with the conversion of one to the other upon receptor binding representing a slow but potentially significant ...
Cis-trans isomers belong to a class of stereoisomers known as diastereomers and are often referred to as geometric isomers, although this is an obsolete term. Cis-trans stereoisomers normally cannot be interconverted at room temperature, because to do so requires the breaking and reforming of che...
Concomitantly, these L, L-cis and D, L-trans isomers were more populated in the Phe-Xxx as compared to the Ala-Xxx sequences (Xxx = the imino acid). The results are explained in terms of an attractive interaction between the aromatic ring and the succeeding amide bond.WEIGUO...
ChemInform Abstract: Synthesis and X-Ray Structure of cis-1,3-Di-tert-butyl-2,4-bis(pentafluorophenoxy)-1,3,2,4-diazadiphosphetidine I), when allowed to react with the Li salt (II), yields a mixture of diastereomers (yield 70%) with the major isomer (III). WA Kamil,MR Bond,JM...
Surprisingly, these high concentrations were not associated with a clear therapeutic effect in dermatoses (e.g. psoriasis) which are usually responsive to oral retinoids. Interactions between the cis and trans isomers formed in vivo may explain the difference in therapeutic activity of each ...
A chemo-, regio-, and stereoselectively controlled reaction is highly desirable, yet challenging in organic synthesis. Diversely substituted cis and trans isomers of 2-alkyl-3-pyrrolidinols, 5-alkyl-4-hydroxy-2-pyrrolidinones, β-hydroxy--amino acids, and their higher homologues are key ...
The optical resolution of both isomers is carried out using fractional crystallization methods. Polymers of optically active cis- and trans-5-isopropylproline are obtained by ring-opening polymerization of the corresponding N- carboxyanhydrides. Low yields encountered in the polymerization of poly(cis-5...
-4-methyltetrahydropyran which comprise preferably at least 70% by weight, particularly preferably at least 80% by weight, in particular at least 90% by weight, of cis-2-(2-methylprop-1-enyl)-4-methyltetrahydropyran, based on the total amount of cis and trans isomers in the composition....
The H2 and CH4, chemical ionization mass spectra of the cis dicarboxylic acids, maleic and citraconic acid, show much more extensive loss of H2O from [MH]+ than the trans isomers, fumaric acid and mesaconic acid. Similarly, esters of mal... CAM Attwell - 《Biological Mass Spectrometry》 ...
Such isomers are illustrated below, taking the structure wherein n=2 for instance. Similar isomers are produced when n is 3. The present invention is intended to embrace all these isomers under the scope thereof. The cyclopropyl moiety may have further substituents, for example, a fluorine ...