Condensation of (S)-penicillamine methyl or ethyl ester hydrochloride with salicylaldehyde and its C-5 derivatives, provided the diastereomeric thiazolidine derivatives 1 and 2 . The resulting amino function was acylated to afford the amides 3 and 4. Cyclization of the latter led to the 2,3-dihydro-11bH-thiazolo[3,2-d]-[1,4]benzoxazepin-5-(6H)ones 5 and 6. Conformational data for these heterocyclic compounds are discussed. 相似文献
Summary The properties of the matrix which allows the translation of the centre of the expansion in terms of spherical partial waves
of a wave function are examined here. It is shown that the matrix can be decomposed in the product of commuting matrices relative
to preassigned directions, for example the directions of the axes of the reference frame. Furthermore, an exponential form
of that matrix is obtained.
Work supported by C.N.R. and M.P.I. 相似文献
Epoxidation of alkenes and oxidation of thioanisole to the corresponding sulfoxide was achieved using the 1-alkoxycarbonyl- or 1-acyl-v-triazolo[4,5-6]pyridine/hydrogen peroxide systems. High yields of epoxide or sulfoxide were observed when some amide-type triazolides were employed for the oxidizing method. 相似文献
Selective protection of the 3-amino group of 2,3-diaminopyridine with benzyl chloroformate allows a new synthesis of 3-methylamino- and 3-amino-2-alkylaminopyridines. The preparation of 1- and 3-alkoxycarbonyl-v-triazolo[4,5-b]pyridines is also reported. 相似文献
Conversion of N-protected β-hydroxy-α-amino esters to corresponding didehydroamino esters has been achieved using phenyltriflimide/triethylamine as a mild dehydrating agent. The selective formation of didehydroalanine derivatives from dipeptides containing, beside a serine residue, another β-hydroxy-α-amino acid, is also described. 相似文献
Early diagnosis of acute myocardial infarction (AMI) is of outmost importance to reduce the mortality rate, and cardiac troponins are considered the gold standard biomarkers of myocardial necrosis. In this scenario, the characterization of two troponin T (TnT)-binding aptamers as viable alternative to antibodies employed on clinical immunoassays is here reported for the first time. Their recognition ability was first investigated through surface plasmon resonance (SPR). Subsequently, an enzyme-linked oligonucleotide assay (ELONA) was developed on common 96-well polystyrene plates, both by direct and sandwich detection strategies for comparison. In both cases, the assay exhibits a detection ability of TnT in the range of low nanomolar but a great advantage on serum interference was obtained by using both aptamers in a sandwich format, with excellent reproducibility and recovery values. Despite the sensitivity needing to be enhanced to the low picomolar range, these results are encouraging for the development of new, low-cost, and rapid antibody-free colorimetric assays for AMI studies based on aptamer–Troponin T recognition.
The synthesis of linear dipeptides containing N-protected L-phenylalanine and (3R-cis)-tetrahydro-1,4-thiazine-3,5-dicarboxylic acid dialkyl diester residues is described. N-Deprotection of these dipeptides by hydrogenolysis on palladium afforded directly a mixture of cis and trans dioxopiperazines. The stereochemistry and the solution conformational properties of the cyclic dipeptides are determined. 相似文献