Cyanoacetylene and Its Derivatives: XXXIV. Nucleophilic Addition of Tetrazole to Cyanoacetylenes

Nucleophilic addition of tetrazole to 4-hydroxy-4-alkyl-2-alkynonitriles and to 3-phenyl-2-propynonitrile occurred regiospecifically and afforded E-, Z-4-hydroxy-4-methyl-3-tetrazolyl-2-alkenonitriles and 3-tetrazolyl-3-phenyl-2-propenonitrile [20–40°C, 13–50 h, 4–15 wt% MOH (M = Na, K), THF (or DMSO)] in up to 69% yield. The attempt to perform cyclization of the hydroxy-containing adducts into iminodihydrofurans (KOH, ethanol, 23-25°C) resulted in vinyl nucleophilic substitution of the tetrazole moiety by an ethoxy group.     

Using synchrotron radiation to study the structure of calcium-phosphate films on the surfaces of medical implants

In situ X-ray diffractometry with synchrotron radiation (SR) is used to study structural transformations in thin films of calcium-phosphate on the surfaces of medical implants made from alumina ceramics and oxidized titanium. The temperature limits of crystallization and structural composition of films on various substrates are found.     

The free convection of a fluid with an initial vertical density gradient and lateral heating

Some results are given of an experimental investigation into the free convection in solutions with density which is nonuniform with height. It is shown that convective motion in solutions with a vertical density gradient and lateral heating is cellular in nature. The height of the cells is determined as a function of the temperature head and the density gradient.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 1, pp. 123–126, January–February, 1971.     

Ferrocenyltriazoles from 3β,28-Diacylbetulin: Synthesis and Cytotoxic Activity

Russian Journal of Organic Chemistry - The reaction of 30-bromo-3β,28-diacylbetulin with sodium azide afforded 30-azido-3β,28-diacyloxylup-20(29)-enes. The products were subjected to a...     

Stereochemical study of iminodihydrofurans based on experimental measurements and SOPPA calculations of (13)C-(13)C spin-spin coupling constants

Configurational assignment and conformational analysis of a series of iminodihydrofurans obtained from cyanoacetylenic alcohols were performed on the basis of experimental measurements and high-level ab initio calculations of their (13)C-(13)C spin-spin coupling constants. The title compounds were shown to form and exist in solution as the individual Z isomers, adopting the orthogonal orientation of the amino, alkylamino and dialkylamino groups and the s-trans orientation of the CONH(2) group at the C(4) position of the 2,5-dihydro-2-iminofuran moiety.     

Synthesis of Di- and Triterpenoid Ferrocenyltriazoles

Ferrocene conjugates with a lupane triterpenoid linked through a triazole ring and C₃ or C₆ hydrocarbon tether were synthesized by reaction of ferrocenylalkylazides with betulonic acid propargyl ester. Analogous conjugates were obtained from dehydroabietic acid propargyl ester.     

DBU as a scaffold for the synthesis of [1,3]oxazolo[2’,3’ : 2,3]pyrimido-[1,2-a]azepines: annulation with aromatic cyanopropargylic alcohols

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