The formation of macrocyclic pseudo-tetrasaccharide derivative of d-glucosamine as a result of the acid-catalyzed reaction between 2-methyl- and 2-(2,2,2-trichloroethoxy)-substituted oxazoline ...derivatives of sugars was discovered. The structure of the obtained product was determined using NMR spectroscopy and mass spectrometry. An explanation of the obtained results based on the mechanism of the reaction of electrophilic polymerization of 2-substituted glyco-2,1-d-2-oxazolines and the principle of hard and soft acids and bases (HSAB) was proposed.
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•Alternating copolymerization of 2-substituted glyco-2,1-d-2-oxazolines was revealed.•Cyclic tetrasaccharide forms by the reaction of 2-alkyl and 2-alkoxy glucooxazolines.•The HSAB concept provides an explanation for the formation of the alternating sequence of monosaccharide residues.
New methods for the synthesis of the title oxazoline 2 from the corresponding 2-deoxy-2-(2,2,2- trichloroethoxycarbonylamino)glucosyl bromide were developed. The target 2-(2,2,2-trichloroethoxy) ...gluco-2,1-d-2-oxazoline 2 can be synthesized under conditions of halide ion catalysis, using triethylamine as a base. The synthesized 2-(2,2,2-trichloroethoxy)-2-oxazoline glycosyl donor was used for stereo-, regio-, and chemoselective glycosylation reactions under extremely mild conditions. The undesirable side reaction of intermolecular aglycone transfer between an ethyl thioglycoside glycosyl acceptor and the 2-(2,2,2-trichloroethoxy)-2-oxazoline glycosyl donor occurred to a relatively small extent. Regio-, and chemoselectivity of the disaccharide synthesis with the oxazoline glycosyl donor depended on the reaction conditions.
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•Two methods for the synthesis of alkoxy oxazoline glycosyl donor 2 were developed.•The obtained donor is used for stereo- regio- and chemoselective synthesis of N-Troc protected oligosaccharides.•The intermolecular aglycon transfer occurs to a small extent at glycosylation by donor 2.•Regio- and chemoselectivity depends on conditions of the oligosaccharide synthesis.
In the methodology of teaching literature and in school practice, traditionally much attention is paid to the problem of interdisciplinary connections, while the issues of intra-disciplinary ...interaction of literary material within the school course are not sufficiently developed by methodologists. The presence of this problem is felt especially acute in the study of literature in high school, when students ' knowledge is generalized not only at the synchronic, but also diachronic levels. With consistent updating of various levels of artistic communication, the study of the historical and literary course acquires a broad dialogical focus, forming the skills of contextual examination of literary phenomena in students. In this article, we will consider building intra-disciplinary relations in the lessons of studying modern Russian poetry at school. First, various artistic universals (archetypes, mythologems, topos, "eternal" motives) are actualized, which have important methodological significance and allow students to make broad historical and cultural generalizations at the lessons. Holistic comprehension of a work of art in the context of the historical and literary process is determined by the definition of various types of intertext artistic interactions (borrowings, imitations, parodies, reminiscences, citations) reflecting the principle of continuity of literary phenomena. At the same time, it is very important to identify historical and biographical ties, a creative dialogue between contemporary poets and poets of various eras. It can be mentoring, apprenticeship, co-authorship, rivalry, continuity, tradition actualization, "attraction - repulsion" type of relationships, influence, and others.
In the article the basic methodological problems associated with the return of the final essay to the Russian school practice have been considered. The synchronic and diachronic analysis provided in ...the article defines a meta-methodological character of an essay, recreating the criteria of assessment, thematic and genre transformation of an essay as the basic conditions for its success. The article contains different views of scientists on further improvement of this form of final control.
Article is devoted to studying the specifics of teaching modern Russian poetry in the context of the Russian and Tatar cultures’ dialogue in system of school education of the Tatarstan Republic ...featuring teaching two state languages - Russian and Tatar.Relevance of this research is caused by theoretical and practical readiness of a technique for teaching the Russian poetry of the second half of the XX century - the first decade of the 21st century in the senior classes of schools with native (Tatar) language of training. In this research the technique of teaching modern Russian poetry developed by us in the context of the Russian and Tatar cultures’ dialogue approved in practice of teaching literature in the 11th class of the Tatar gymnasium No. 2 of Kazan is presented.The conducted research allows us to draw conclusions that use of dialogue of cultures promotes increase in efficiency of studying the Russian literature by Tatar students due to activization of their bicultural potential. On the example of the out-of-class lesson devoted to I. A. Brodsky, A. S. Kouchnerand O. G. Chukhontsev's philosophical poetry the technique of studying the poems of these poets taking into account features of perception by Tatar students of the Russian literature as nonnative is for the first time presented.The analysis of skilled and experimental training results showed that the successful solution of the problem of teaching modern Russian literature in foreign-language audience is promoted use at lessons of convincing facts about the similar phenomena in Russian and native (Tatar) literatures, detection of the works similar on subject, close in the problem and genre relations, the appeal to the translations of works of the Russian writers on native (Tatar) language.At a lesson of a home reading group methods of the student work organization, as well as various kinds of student activity were used: expressive reading of poems by I. A. Brodsky, A. S. Kouchner and O.G. Chukhontsev devoted to time subject, oral performances of students with reports and messages on creativity specifics of modern Russians and Tatar poets R. M. Haris, R. G. Fayzulin, Zulfat, carrying out complex, comparative, comparative and typological analyses of poems of the Russian and Tatar poets, professional literary poems’ translations of the modern Tatar poets into Russian, as well as creation by students of the word for word translations of poems of I. A. Brodsky, A. S. Kouchner and O. G. Chukhontsev into Tatar (due to the lack of their professional literary translations).
Fetal sex prognostication has been a common practice in many human societies, yet most of the prognosticative methods do not perform better than chance. Why do these ineffective prognostication ...practices recur across societies and persist for long periods of time? In this article, we use historical texts of four different genres in traditional China (oracle bone inscriptions, dynastic history, encyclopedia, and local gazetteers) to examine the social and cognitive factors that lead to the overestimation of the predictive accuracy of sex prognostication and place fetal sex prognostication into a more general framework to understand the persistence of ineffective cultural practices. In particular, we present a detailed historical analysis showing that individuals often entertain considerable uncertainty regarding the accuracy of sex prognostication and quantitative data demonstrating a significant bias toward selectively reporting successes in (fictionalized) historical texts. We conclude by discussing how such reporting bias combined with humans’ imperfect information processing may help explain the persistence of ineffective technologies, such as divination, and magic in general.
Resumen
El pronóstico del sexo del feto ha sido una práctica común en muchas sociedades humanas, sin embargo, la mayoría de los métodos de pronóstico no son mejores que el azar. ¿Por qué estas prácticas ineficaces de pronóstico son recurrentes a través de las sociedades y persisten por largos períodos de tiempo? En este artículo, usamos textos históricos de cuatro diferentes géneros en la China tradicional (inscripciones en huesos de oráculos, historias de dinastías, enciclopedias y gaceteros locales) para examinar los factores sociales y cognitivos que llevan a la sobreestimación de la exactitud predictiva del pronóstico del sexo y situar el pronóstico del sexo del feto en un marco más general para entender la persistencia de prácticas culturales ineficientes. En particular, presentamos un análisis histórico detallado mostrando que los individuos a menudo tienen un nivel de incertidumbre considerable en relación con la exactitud del pronóstico del sexo, y datos cuantitativos demostrando un sesgo significativo reportando selectivamente éxitos en textos históricos (vueltos ficción). Concluimos discutiendo cómo este reporte de sesgo combinado con el procesamiento de información imperfecta de los seres humanos puede ayudar a explicar la persistencia de tecnologías ineficaces, tales como la adivinación y la magia en general. evolución cultural, cognición, adivinación, sexo fetal, China
in Chinese
辨胎行為在人類社會中屢見不鮮, 但絕大多數辨胎方法的成功率並不比隨機預測高。這些無效的辨胎行為為何在人類社會的歷史上反復出現並長久延續？在本文中, 我們使用了中國古代四種不同類型的歷史文本 (甲骨文、正史、類書和地方誌) , 來考察導致高估辨胎準確性被高估的社會性和認知性因素, 並將辨胎行為納入一個更普遍的框架之中, 以解釋無效文化習俗的延續。具體來說, 我們通過對歷史材料的詳細分析來說明, 人類個體通常能夠意識到辨胎方法具有相當大的不確定性;而定量資料表明, 在 (虛構的) 歷史文本中存在選擇性報告成功預測的顯著偏見。最後, 我們得出結論, 這種報告偏見與人類不完善的資訊處理方式使占卜和巫術等無效技術得以持續存在
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