Allylbutyltin halides (CH2CHCH2)SnBu3−nCln (n = 0, 1, 2, 3). Preparation,carbon-13 NMR characterization and allylstannylation ability towards ketones and aldehydes

Mixed allylbutyltin halides (CH₂CHCH₂)SnBu_3-nCl_n (n = 0–3) have been prepared, and characterized by carbon-13 NMR spectroscopy. Their ability to bring about allylstannylation of ketones and aldehydes, to form organostannoxy compounds, Bu_3-nSnCl_nOC(R′)(R″)CH₂CHCH₂, has been shown to increase on increasing the value of n, that is on increasing the acceptor ability of the tin centre.     

X-ray and mössbauer studies of tricyclohexyltin(IV) halides. The crystal structures of (cyclo-C6H11)3SnX (X = F,Br and I)

The structures of tricyclohexyltin fluoride (I), bromide (II) and iodide (III) have been determined by X-ray analysis. Compound I crystallizes in the space group P2₁/m with a = 10.422(6), b = 17.238(9), c = 5.769(3) Å, β = 104.6(1)° and Z = 2. Compounds II and III crystallize in the space group Pcmn with a = 10.427(6), b = 16.914(9), c = 11.366(6) Å, Z = 4; and a = 10.400(6), b = 16.900(10), c = 11.400(4) Å, Z = 4, respectively. All three structures consist of discrete tetrahedral (cyclo-C₆H₁₁)₃SnX units.The temperature dependence of the Mössbauer resonance areas has been examined in order to obtain information about the relationship between chemical structure and lattice dynamics.     

18-Deoxyaldosterone,its chemical and microbial reduction products

Reduction of the diketal 1 with sodium aluminum bis-(methoxyethoxy) hydride afforded the crystalline 18-hydroxycorticosterone diketal (2), an intermediate in the formation of 18-deoxyaldosterone acetate (4b). The hitherto unreported but anticipated metabolites of 4 were prepared as follows: hydrogenations of 4b furnished the fα- and 5β isomers 6 and 5b, and thence the tetra- and hexahydro derivatives 10, 11, 8, 9 and 7, and the 3-deoxy compounds 12 and 13. Anaerobic fermentations of 4b with Clostridium paraputrificum gave the tetrahydro derivative 8b in high yield.     

Pulse polarography: VIII. A new digital to analog pulse polarograph

A new pulse polarograph for normal mode instantaneous current sampling with digital control of timing and of potential generation, is described. Pulse times and delay times are independently variable over a wide range. Pulse times can be varied in 10 ms intervals. The performance of the instrument has been tested in the determination of pulse-polarographic diffusion coefficients of Tl⁺, Cd²⁺, Co(III)(en)₃³⁺ and Co(NH₃)₆³⁺. The reproducibility was found to be excellent.     

The chemistry of chromyl fluoride III. Reactions with inorganic systems

Reactions of CrO₂F₂ with MF or MF₂ gave the corresponding M₂CrO₂F₄ and MCrO₂F₄ fluorochromates. With the Lewis Acids (SO₃, TaF₅, SbF₅) and (CF₃CO)₂O known and new chromyl compounds [CrO₂(CF₃COO)₂, CrO₂(SO₃F)₂, CrO₂FTaF₆, CrO₂FSbF₆, CrO₂FSb₂F₁₁] were produced. Chromyl fluoride and inorganic salts (CF₃COONa and NaNO₃) produced the following complexes - Na₂CrO₂F₂(CF₃COO)₂ and Na₂CrO₂F₂(NO₃)₂. Unusual solid products were obtained with CrO₂F₂ and NO, NO₂, SO₂.A new method of preparing CrO₂F₂ is also presented.     

Studies of acenaphthene derivatives—XXVIII : The reaction of 2-diazoacenaphthenone with anils in the presence of boron trifluoride

Reaction of 2-diazoacenaphthenone with anils in the presence of a catalytic amount of boron trifluoride etherate is reported. The diazoketone reacts with benzylidenanilines to afford a mixture of stereoisomers of spiro[acenaphthenone-2′,4-imidazolidine], whose structures correspond to compounds derived from 1:2 adducts of the diazoketone and anils with the elimination of nitrogen. A pathway involving spiro-aziridine intermediates is proposed for their formation. Reaction of the diazoketone with aα-alkylbenzylidenanilines however gives the corresponding acenaphtho[1,2-b]pyrroles, whose structures correspond to compounds arising from 1:1 adducts with the elimination of both nitrogen and water. The reaction of the tautomeric enamine form of the anil with a carbenoid intermediate generated from the diazoketone is suggested for pyrrole formation.     

Organic halide-ethylene growth reaction catalyzed by ruthenium complexes

Ru(CO)₃(PPh₃)₂ and a variety of other zero-valent ruthenium complexes promote the reaction of iodoalkanes with ethylene to produce higher molecular weight 1-iodoalkanes. The chemistry is best explained by the intermediacy of alkyl radicals generated by reaction of the ruthenium complexes with iodoalkanes. With the exception of α-chlorotoluene, organic bromides and chlorides do not undergo the growth reaction.     

Syntheses and properties of H-1,2,3-triazoles

About twenty new H-1,2,3-triazoles (T) were readily synthesized by nucleophilic attack of sodium azide on activated acetylenes in dimethylformamide. Typical activating groups were COR, COOR, O₂NC₆H₄ PO(OC₂H₅, COT, and (C₆H₅)₃P⁺. Propynyl 4-triazolyl ketone or phenylethynyl 4-triazolyl ketone may be converted to acylic adducts (triazolylketoenamines), biheteroaromatic systems (isoxazolytriazoles, pyrazolytriazoles), as well as to ditriazolyl ketones. Certain T properties were examined in detail. The apparent pK′s for our group of ca 30 triazoles were in the range 4·95?9·45 in ethanol-water (v/v 1/1) at 25°. The Hammett correlation for five 4-aryl-T was log K_a = 0·89σ^? ?9·21 and for seven 4-aryl-5-carbethoxy-T was log K_a = 1·45σ?6·95. The UV spectra of T are similar to those of other heteroaromatic and phenyl compounds: interesting analogies between triazolyl and phenyl, e.g., ”ortho“ crowding effects, appear to be indicated in the spectra of compounds related to biphenyl, stilhene and benzophenone. With regard to structure assignment on the basis of spectra, characteristic features of UV and IR spectra of the H-1,2,3-triazoles are discussed.     

Pinnatanine and oxypinnatanine,novel amino acid amides from Staphylea pinnata L.

Two novel amino acids amides, pinnatanine and oxypinnatanine, have been isolated from Staphylea pinnata L. Their respective structures have been established as N⁵-(2-hydroxymethylbutadienyl)-l-allo-γ-hydroxyglutamine and N⁵-(3-hydroxymethyl-2,5-dihydro-2-furyl)-l-allo-γ-hydroxyglutamine by spectral methods and chemical degradation.     

Oxygen evolution on SrFeO3 electrode

Oxygen evolution reactions on SrFeO₃ were investigated in alkaline and acidic solutions. It was found that the catalytic activity for the oxygen evolution reaction in the alkaline solution is high. The following reaction steps (V)+Fe+2H₂O→(O)+FeOH₂+2H⁺+2e^? in acidic solution and FeOH+OH^?→FeO^?+H₂O in alkaline solution are presumed to be rate-controlling in the anodic evolution of oxygen on SrFeO₃ electrode, where (V) denotes oxygen vacancy on the electrode surface. The reaction mechanism and the catalytic property are discussed in connection to the band structure of the oxide.     

Hexabromocyclopentadiene V. The Diels-Alder reaction of hexabromocyclopentadiene

The reactivity of hexabromocyclopentadiene (1) as a diene in the Diels-Alder reaction has been determined with a number of dienophiles. The results of the present study show that 1 behaves as an electron-poor diene in that cyclopentadiene is a more reactive dienophile than maleic anhydride. Qualitatively, 1 has been found to be a less reactive diene than hexachlorocyclopentadiene. Several new Diels-Alder adducts of 5,5-dibromo-1,2,3,4-tetrachlorocyclopentadiene are also reported.     

The structures of evonine and neoevonine alkaloids obtained from Euonymus Sieboldiana blume

Evonine (1) and neoevonine (2) were isolated from Euonymus Sieboldiana Blume. The structural studies of the principal alkaloid, evonine were carried out extensively by chemical and spectroscopic methods, resulting in the establishment of the structure of the alkaloid as 1: it is a highly oxygenated sesquiterpene of eudesman type, which is esterified with five moles of acetic acid and evoninic acid (33). The derivatives for the structure determination of 1 are summarized in Charts I–III. Interconversion of the two alkaloids, (1 and 2) was achieved and the structure of neoevonine was elucidated as 2.