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1.
T. S. Raikova G. V. Kalechits E. N. Manukov T. K. Vyalimyae S. A. Makhach 《Chemistry of Natural Compounds》1981,17(6):526-530
The conditions for the acylation of (?)-menthol with monochloroacetyl chloride have been studied. Amino esters of (?)-menthol have been obtained by the nucleophilic replacement of the chlorine in (?)-menthol monochloroacetate by residues of secondary amines. Their properties and their mass, IR, and13C NMR spectra are described. 相似文献
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Gulay Zengin 《Chemistry of Natural Compounds》2011,47(4):550-555
This study concentrates on the extraction of eugenol, menthol, and genistein, and the synthesis, antimicrobial activity, and
structure-activity relationships of their ester derivatives. The esters were tested for antimicrobial activity against several
bacteria and yeast, and the correlation between biological properties and various physicochemical properties was examined.
The ester derivatives gave intense emissions upon irradiation by UV light and have photoluminescence quantum yields of 39,
35, and 36% and long excited-state lifetimes of 3.62, 3.23, and 3.40 ns, respectively. These esters may be used in herbal
medicinal therapy, and additionally as a base for the development of new drugs for phytomedicine. 相似文献
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Cíntia Salomão Pinto Zarth Andreas Koschella Annett Pfeifer Susann Dorn Thomas Heinze 《Cellulose (London, England)》2011,18(5):1315-1325
The homogeneous conversion of cellulose dissolved in N-methyl-2-pyrrolidone/LiCl and 1-N-butyl-3-methylimidazolium chloride with N-methyl-2-pyrrolidone, ε-caprolactam, N-methyl-ε-caprolactam, and N-methyl-2-piperidone in the presence of p-toluenesulphonic acid chloride was studied. Depending on the reaction conditions, novel cellulose esters with degree of substitution
(DS) values ranging from 0.12 to 1.17 could be prepared. The structure of the amino group containing cellulose esters was
elucidated by elemental analysis, FTIR- and NMR spectroscopy. NMR spectroscopy revealed an almost complete esterification
of position 6 of the anhydroglucose unit at DS of 1. The conversion can be conducted between room temperature and 40 °C, while
side-reactions became predominant at 60 °C. Starting with DS of 0.24, the samples were soluble both in water and dimethyl
sulphoxide. The derivatives described are capable of forming polyelectrolyte complexes. The samples were stable at room temperature
in aqueous solution at pH 2 and 7. Lower viscosities were found for samples with higher DS in aqueous solution at comparable
molar mass. 相似文献
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《Tetrahedron》1987,43(8):1823-1826
A wide range of N-Boc-amino add esters were synthesized from N-Boc-amino acids and alcohol using papain as catalyst. Suitable biphasic reaction mixtures were found for most amino acids to achieve high yield of ester synthesis. With N-Boc-L-aspartic and glutamic adds only the a carboxyl group is esterified, without racemisation. 相似文献
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Fareha Zafar Khan Masashi Shiotsuki Fumio Sanda Yoshiyuki Nishio Toshio Masuda 《Journal of polymer science. Part A, Polymer chemistry》2008,46(7):2326-2334
The amino acid esters of hydroxypropyl cellulose (HPC) [R′ = H ( 2a ), CH3 ( 2b ), CH2CH(CH3)2 ( 2c ), CH2CONH2 ( 2d ), CH2CH2CONH2 ( 2e ), CH2CH2CH2CH2 NHOCOC(CH3)3 ( 2f )] were synthesized in good yield by the reaction of t‐butoxycarbonyl (t‐Boc)‐protected amino acids with hydroxy groups of HPC ( 1 ; molar substitution (MS), 4.61). The amino acid functionalities displaying varied chemical nature, shape, and bulk were utilized and the bulk of the substituent on the α‐carbon of amino acids was elucidated to be of vital significance for the observed degree of incorporation (DSEst). The 1H NMR spectra and elemental analysis were employed to determine the degree of incorporation of amino acid moiety (DSEst) and almost complete substitution of the hydroxy protons was revealed for 2a , 2b , and 2f . The presence of the peaks characteristic of the carbonyl group in the FTIR spectra furnished further evidence for the successful esterification of HPC. The starting as well as the resulting polymers ( 1 and 2a – f ) were soluble in polar organic solvents; however, the esterification of 1 with bulky organic moieties resulted in an increased hydrophobicity as all of the amino acid‐functionalized polymers ( 2a – f ) were insoluble in water. The onset temperatures of weight loss of 2a – f were 175–230 °C, indicating fair thermal stability. The amino acid functionalization led to the enhanced polymer chain stiffness, and the glass transition temperatures of the derivatized polymers were 30–40 °C higher than that of 1 (Tg 3.9 °C; cf. Tg of 2a – f , 35.1–43.3 °C). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2326–2334, 2008 相似文献
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L. M. Bogomolova Yu. B. Pyatnova A. A. Savina V. S. Smolyakov V. P. Zvolinskii 《Chemistry of Heterocyclic Compounds》1976,12(4):382-385
New tetrahydro-1,2-oxazine-N-dithiocarboxylic acid esters were synthesized, and their structures were investigated by IR and PMR spectroscopy and mass spectrometry.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 454–458, April, 1976. 相似文献
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N. A. Zhukovskaya E. A. Dikusar V. I. Potkin O. G. Vyglazov 《Chemistry of Natural Compounds》2009,45(2):148-151
Preparative syntheses from anisaldehyde 1 of the anti-isomer of anisaldehyde oxime 2 and anisaldehyde oxime esters 3a-q in 84-93% yields were developed. The structure—aroma correlation of 2 and 3a-q was studied.
Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 131-134, March-April, 2009. 相似文献
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As part of our ongoing project to develop new molecular probes for estrogen receptor-alpha, we are exploring the utility of internally-substituted asymmetric biphenyls as a proteomimetic scaffold. In this study, we describe synthetic methods for preparing the requisite substituted-bromophenol precursors, their further elaboration, and the subsequent Suzuki–Miyaura coupling of these sterically-hindered and electronically-rich aromatic systems. The results provide an efficient route with which to generate further libraries of novel asymmetric biphenyl compounds as potential proteomimetics. 相似文献
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Jian‐She Hu Dan Li Wen‐Chang Zhang Qing‐Bao Meng 《Journal of polymer science. Part A, Polymer chemistry》2012,50(24):5049-5059
To study structure–mesomorphism relationships of the monomers and polymers based on menthol, four new chiral monomers ( M1 – M4 ) and the corresponding homopolymers ( P1 – P4 ) with menthyl group were synthesized. Their chemical structures, formula, phase behavior, and thermal stability were characterized by FTIR, 1H NMR, 13C NMR, elemental analyses, differential scanning calorimetry, polarizing optical microscopy, X‐ray diffraction, and thermogravimetric analysis. The selective reflection of light was investigated with ultraviolet/visible spectrometer. The influence of the mesogenic core rigidity, spacer length, and menthyl steric effect on the mesomorphism of M1 – M4 and P1 – P4 was examined. By inserting a flexible spacer between the mesogenic core and the terminal menthyl groups, four target monomers and polymers could form the expected mesophase. Moreover, their melting temperature (Tm), glass transition temperature (Tg), clearing temperature (Ti), and mesophase range (ΔT) increased with increasing the mesogenic core rigidity; whereas the Tm and Tg decreased, Ti and ΔT increased with an increase of the spacer length. M1 and M2 showed monotropic and enantiotropic cholesteric phase, respectively, whereas M3 and M4 all revealed chiral smectic C (SmC*), cholesteric and cubic blue phases. In addition, with increasing temperature, the selective reflection of light shifted to the long wavelength region at the SmC* phase range and to the short wavelength region at the cholesteric range, respectively. P1 and P2 only showed a smectic A (SmA) phase, whereas P3 and P4 exhibited the SmC* and SmA phases. All the obtained polymers had very good thermal stability. © 2012 Wiley Periodicals, Inc. J. Polym. Sci. Part A: Polym Chem, 2012 相似文献
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N-Benzyloxycarbonylendothiodipeptide esters, 3, are synthesized without racemization from the corresponding N-benzyloxycarbonyldipeptide esters, 2, using 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide, 1, as thionation reagent. The benzyloxycarbonyl amino-protecting group (Z) is removed from 3 by using HBr-AcOH. 相似文献
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A synthesis of aziridine esters based on the cyclisation of amino selanyl esters induced by the selanyl group activation was developed with either the Meerwein salt or NBS. Two asymmetric approaches are proposed: the diastereoselective reductions of α-selanyl β-iminoesters derived from α-oxoesters, which lead to cis chiral aziridine esters 6 and 6′; and the diastereoselective conjugate additions of a chiral amide to α,β-unsaturated esters providing trans chiral aziridine esters 6 and 6″. 相似文献
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We report a synthetic route to ansa pyrrole amino acids via olefin ring-closing metathesis of diene precursors in the presence of Grubbs I catalyst. The dienes were prepared by Grignard addition to pyrrole sulfinyl imines. The success of the macrocyclic ring closure depends on the dienes structure and only in the case of the 13-membered compound 28 sufficient material could be isolated by preparative HPLC separation to investigate its structure spectroscopically. As also rationalized by our computations at the B3LYP/6-311+G(d,p)//B3LYP/6-31G(d) level of theory, 28 is configurationally stable. 相似文献