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91.
A. V. Shernyukov I. Ya. Mainagashev D. V. Korchagina Yu. V. Gatilov N. F. Salakhutdinov G. A. Tolstikov 《Chemistry of Natural Compounds》2011,47(2):237-242
Reduced derivatives of 2,3-seco-28-oxo-19β,28-epoxy-18α-olean-2,3-dicarboxylic acid and its cyclic anhydride were prepared. Reduction of the starting 2,3-secodicarboxylic acid by
NaBH4–I2 produced the 2,3-seco-2,3-dihydroxy derivative. Reaction of the starting anhydride with LiAlH4 gave the 2,3-seco2,3,19β,28-tetrahydroxy derivative. Cyclization using acidic reagents of the 2,3-seco-2,3-hydroxy- and 2,3seco-2,3,19β,28-tetrahydroxy derivatives gave the corresponding cyclic ethers containing an oxepane ring. The anhydride ring was reduced
by NaBH4 to the corresponding ε-lactone, the structure of which was confirmed by an x-ray crystal structure. 相似文献
92.
93.
94.
O. I. Yarovaya D. V. Korchagina N. F. Salakhutdinov G. A. Tolstikov 《Chemistry of Natural Compounds》2012,48(1):56-59
The reactions of isocembrol with allyl and methyl alcohols on K-10 clay were studied. 相似文献
95.
Vorozhtsov Nikolai O. Yarovaya Olga I. Roznyatovskii Vitalii A. Tarasevich Boris N. Kozlovskaya Yuliya A. Petkova Aneliya I. Slita Aleksander V. Sinegubova Ekaterina O. Zarubaev Vladimir V. Salakhutdinov Nariman F. Beloglazkina Elena K. 《Chemistry of Heterocyclic Compounds》2021,57(4):432-441
Chemistry of Heterocyclic Compounds - For the first time, convenient methods for the preparation of pyrazoline N-alkylidene salts based on terpene (camphor, camphorquinone, carvone) ketones, cage... 相似文献
96.
V. I. Anikeev I. V. Il’ina S. Yu. Kurbakova A. A. Nefedov K. P. Volcho N. F. Salakhutdinov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(2):190-195
The reactivity of monoterpene α-pinene in a flow reactor in the presence of cobalt catalyst in a complex supercritical solvent
consisting of CO2 and ethyl acetate is studied over the temperature range of 190–320°C and a pressure range of 110–125 atm. It was found that
the main isomerization products include compounds with bicyclo[2.2.1]heptane and p-menthane backbones; the reaction is accompanied by partial racemization. The formation of oxidation products is observed
in the presence of air, with epoxydation rather than allylic oxidation being the predominant process at the first stage. The
oxidized products (campholenic aldehyde, verbenone, pinocamphone) are shown to be formed with a high enantioselectivity; the
formation of acetoxylation products is observed at temperatures above 200°C. 相似文献
97.
A. A. Tazetdinova O. A. Luzina M. P. Polovinka N. F. Salakhutdinov G. A. Tolstikov 《Chemistry of Natural Compounds》2009,45(6):800-804
Products from the reaction of usninic acid and 4-(3-aminopropyl)-2,6-di-t-butylphenol, 4-(2-aminoethyl)-2,6-di-t-butylphenol, antipyrine, N,N-diethylaminoethylamine, p-chloroaniline, and p-bromoaniline in addition to the quaternary ammonium salt (E)-2-(1-(6-acetyl-7,9-dihydroxy-8,9b-dimethyl-1,3-dioxo-1,9b-dihydrodibenzo[b,d]furan-2(3H)-ylidene)ethylamino)-N,N-diethyl-N-methylethaneammonium iodide were obtained. 相似文献
98.
Semantic hashing 总被引:1,自引:0,他引:1
We show how to learn a deep graphical model of the word-count vectors obtained from a large set of documents. The values of the latent variables in the deepest layer are easy to infer and give a much better representation of each document than Latent Semantic Analysis. When the deepest layer is forced to use a small number of binary variables (e.g. 32), the graphical model performs “semantic hashing”: Documents are mapped to memory addresses in such a way that semantically similar documents are located at nearby addresses. Documents similar to a query document can then be found by simply accessing all the addresses that differ by only a few bits from the address of the query document. This way of extending the efficiency of hash-coding to approximate matching is much faster than locality sensitive hashing, which is the fastest current method. By using semantic hashing to filter the documents given to TF-IDF, we achieve higher accuracy than applying TF-IDF to the entire document set. 相似文献
99.
In this paper we study C*-algebras generated by a commuting family of isometric operators. Such algebras naturally generalize the Toeplitz algebra.
We investigate *-automorphisms and ideals of C*-algebras generated by semigroups. 相似文献
100.
Mingaleeva G. R. Yakovleva M. P. Salakhutdinov R. R. Tolstikov A. G. Ishmuratov G. Yu. 《Russian Journal of Organic Chemistry》2019,55(4):514-517
Russian Journal of Organic Chemistry - Four potentially biologically active 31-, 32-, and 33-membered macroheterocycles with ester and hydrazide fragments have been synthesized by [1 +... 相似文献