Synthesis, conformational analysis, and bioassay of 9,10-didehydroepothilone D

[reaction: see text] 9,10-Didehydroepothilone D was synthesized, its conformation was studied, and its tubulin polymerization and antiproliferative activity were compared with that of epothilone D and certain analogues.     

Synthesis and bioassay of benzimidazole conjugates with adamantane

The synthesis of 2-adamantyl-6-[(1H-benzimidazol-1-ylcarbonyl)amino]hexanoate and 2-adamantyl-7-(1H-benzimidazol-1-yl)-7-oxo-heptanoate, and the results of their cytotoxicity assay against human lung carcinoma cells A549 are presented in the paper. The impossibility of adding 5-(2-adamantyloxycarbonyl)pentyl isocyanate to nocodazole under various conditions was shown.     

Synthesis,structural characterization and bioassay screening of dimeric bis[dicarboxylatotetraorganodistannoxanes]

Reaction of bis(pyrazol‐1‐yl)acetic acid with n‐Bu₂SnO in a 1:1 molar ratio gives dimeric bis[dicarboxylatotetraorganodistannoxanes], {[(n‐Bu)₂(Pz₂CHCO₂)Sn]₂O}₂ (Pz = pyrazol‐1‐yl or 3,5‐dimethylpyrazol‐1‐yl), which are characterized by IR and NMR (¹H, ¹³C and ¹¹⁹Sn) spectra and elemental analyses. The X‐ray crystal structure analyses indicate that {[(n‐Bu)₂(Pz₂CHCO₂)Sn]₂O}₂ is a centrosymmetric dimer with a cyclic Sn₂O₂ unit, in which each tin atom is situated in a distorted trigonal bipyramidal geometry. In addition, bis(3,5‐dimethylpyrazol‐1‐yl)acetic acid in the solid state forms a dimer through two intermolecular O? H···N hydrogen bonds. These organotin derivatives display low fungicide, insecticide and miticide activities, but display certain cytotoxicities for Hela cells in vitro. Copyright © 2005 John Wiley & Sons, Ltd.     

Synthesis of hedychenone, yunnancoronarins and aframodial derivatives

Starting with larixol, syntheses of furan and 1,4-enedial labdane-type diterpenes are presented, which has enabled a preparation of hedychenone (20% yield).     

Synthesis of oxadiazoloquinoxaline,oxathiadiazoloquinoxaline and oxadiazolobenzothiazine derivatives

Bis‐amidoxime 1 reacts with phosgene, thiophosgene and thionylchloride to give the corresponding bisfused oxadiazolo‐ and oxathiadiazoloquinoxalines 2, 4, 5 along with the unexpected furazano‐derivative 3 , while monoamidoximes 9, 13 by treatment with ethyl chloroformate affords the oxadiazoloquinoxaline and the oxadiazolobenzothiazine derivatives 14, 15 along with the dicarboxylated product 16 .     

Synthesis of porphyrazine-octaamine, hexamine and diamine derivatives

The syntheses of a variety of substituted diaminomaleonitriles, with variable nitrogen substituents, were undertaken. Linstead macrocyclization of the resulting diaminomaleonitriles gave access to a wide range of functionalized porphyrazine-octaamines and hexamines and norphthalocyaninediamines. Conversion of these macrocycles into metallic derivatives and studies of their electronic absorption, solubility and electrochemistry are described. These flexible tetraazaporphyrins show potential in a range of applications including biomedical agents, novel charge-transfer complexes, chemical sensors, novel electronic materials and non-linear optics.     

Synthesis,structure and reactivity of amino-benzodifurane derivatives

The reactivity of amino groups of some dialkyl esters of 2,6-diamino-benzo[1,2-b:4,5-b′]difuran-3,7-dicarboxylic acid towards acylic reactants was investigated. The easy and chemoselective obtainment of the N,N′-acetyl- and N,N′-benzoyl-derivatives makes the diamino compounds suitable monomers to prepare polymers with tunable chemo-physical behavior. Two novel polyamides, potentially useful for applications in the field of organic electronics, were synthesized and their properties examined. Single crystal X-ray analysis was performed on some of the prepared compounds, thus obtaining information on the extent of electronic conjugation. The obtainment of an oxazinone derivative by cyclization reaction of an N,N′-benzoyl ester was also described.     

Total Synthesis of L-Allose,L-Talose,and derivatives.

(1S, 4R, 5S, 6S)-5-exo, 6-exo-(Isopropylidenedioxy)-7-oxabicyclo[2.2.1]heptan-2-one ((?)- 1 ) was transformed with high stereoselectivity to L -allose. Similarly, enantiomer (+)- 1 was transformed into L -talose. The ketones (+)- 1 and (?)- 1 were derived from furan and 1-cyanovinyl (1S)-camphanate and 1-cyanovinyl (1R)-camphanate, respectively.     

Synthesis,structure, and properties of new spirooxindolodibenzodiazepine derivatives

An acid-catalyzed reaction of 3-(2-aminophenylamino)-5,5-dimethylcyclohexen-1-one with isatines leads to the formation of the earlier undescribed 3,3-dimethyl-2,3,4,5,10,11-hexahydrospiro[1H-dibenzo[b,e][1,4]diazepine-11,3′-2H-indole]-1,2′-dione derivatives (6). Spiranes 6 upon heating undergo auto-redox rearrangement with disintegration to 3,3-dimethyl-1,2,3,4-tetrahydrophenazine and the corresponding oxindole. Crystals of four derivatives of compound 6 were studied by X-ray diffraction method.     

Synthesis and separation of racemic, isomeric desoxo-demethyl-cassaine derivatives

For the synthesis of analogues of Erythrophleum alkaloids the tricyclic ketones 3 (trans-anti-trans) and 5 (trans-anti-cis) were prepared. Reaction of 3 and 5 with triethyl phosphonoacetate led to a mixture of cis/trans compounds, which could be separated in a preparative scale into the uniform racemic isomers 8 and 9, 22 and 23 , respectively. Transesterification of these compounds gave the corresponding 2-dimethylamino-ethyl esters.     

Pyrimidine derivatives. VI. Synthesis of mono-, di-, tri-, and tetrabromo-substituted pyrimidine derivatives

The following bromo-2,4(1H,3H)-pyrimidinediones possessing a bromo substituent at the 5-position and side chains at the 1- and 6-positions were prepared. The three types of mono-bromo derivatives are: 1-(bromoalkyl)-3,6-dimethyl- 3a-d , 5-bromo-3,6-dimethyl-1-(hydroxyalkyl)- 4a-d , and 1-(acetoxyalkyl)-5-bromo-3,6-dimethyl-2,4(1H,3H)-pyrimidinediones 11a-d . The three types of dibromo derivatives are: 5-bromo-1-(bromoalkyl)-3,6-dimethyl- Sa-d , 1-(acetoxyalkyl)-5-bromo-6-bromomethyl- 8a, 8c , and 8d , and 5-bromo-6-bromomethyl 1-(hydroxyalkyl)-2,4(1H,3H)-pyrimidinediones 9a, 9c , and 9d . Likewise one group of tribromo and one group of tetrabromo derivatives are: 5-bromo-1-(bromoalkyl)-6-bromomethyl -7a-d and 5-bromo-1-(bromoalkyl)-6-dibromomethyl-2,4(1H,3H)-pyrimidinediones 6a-d .     

Synthesis of aminoacyl derivatives of nucleosides,nucleotides, and polynucleotides

Conclusions The possibility has been shown of extending the method of synthesis of O-aminoacyl derivatives of nucleotides and nucleoside triphosphates to prepare 3(2)-O-peptidyI-micleoside-5-triphosphates.TranslatedfromlzvestiyaAkademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1369–1372, June, 1970.     

Diphenic acid derivatives: Synthesis,reactions, and applications

This review describes the synthesis and reactions of simple diphenic acid derivatives and to highlight the effects of compounds containing the diphenic acid moiety in important applications.     

Synthesis,stereodynamics, and reactivity of isonitrile derivatives of dodecacarbonyltetrairidium

The reaction of Ir₄₍CO)₁₂ with t-BuNC or MeNC in the presence of trimethylamine oxide in refluxing tetrahydrofuran provides the substituted iridium clusters Ir₄(CO)_12-x(RNC)_x] (χ  14; R  t-Bu, Me). The infrared and ¹³C NMR spectra of these molecules indicate that most of them adopt structures related to Ir₄(CO)₁₂, i.e., they have only terminal carbonyl ligands. The variable temperature ¹³C NMR spectra for Ir₄(CO)₁₁(t-BuNC) establish a carbonyl scrambling process which is the formal inverse of the C_3v→ T_d scrambling mechanism proposed for Rh₄(CO)₁₂. The kinetics of substitution of Ir₄(CO)₁₂ by t-BuNC have been studied. Each substitution step occurs by a ligand-dependent, overall second-order reaction at a rate much greater than for substitution by PPh₃. The observed differences between t-BuNC and PPh₃, can be rationalized on the basis of steric differences between the two ligands.