Mass spectrometry of 10-chloro-5, 10-dihydrophenarsazine (adamsite) and 10-methyl-5, 10-dihydrophenarsazine

The mass spectrograms of 10-chloro- and 10-methyl-5,10-dihydrophenarsazine have been determined. These spectrograms show the following main characteristics of fragmentation behavior for these heterocycles: (a) a relative stability, in both compounds, of the arsenic atom within the heterocyclic framework; (b) an exceptionally facile splitting of the As-Cl bond, contrasting with the behavior of the As-CH₃ bond; and (c) an easy formation of the phenarsazine species from 10-chloro-5,10-dihydrophenarsazine.     

SYNTHESIS AND CRYSTAL STRUCTURE OF 5, 10, 15, 20, 22, 24-HEXAHYDRO-5, 5, 10, 10, 15, 15, 20, 20-OCTAMETHYL-PORPHINE

<正> The title com pound (HHOMP) has been synthesized with the pho-toinduced condensation of acetone and pyrrole in the presence of iodoaromatic hydrocarbons, and its molecular and crystal structures have been determined by X-ray analysis. C28H36N4, Mr = 428. 63, triclinic; space group P1; a =10. 165(3), b = 10. 185(2), c=13. 012(3)(?); α=85. 41(2), β=67. 84(2), γ= 89. 75(2)°; V = 1243 (?)3; Z = 2; D = 1. 145g. cm-3; μ= 0. 635cm-1; F (000) = 464. Although the HHOMP molecule twists, it is found that the four nitrogen atoms are still in a plane.     

反式-5,1O,15-三芳基-5,1O,15-三羟基-1-氢-三苯并[a,f,k]三茚的合成与从头算结构分析

合成了两个具有三个羟基的新型主体分子反式－5,10,15－三芳烃－5,10,15－三羟基－1－氢－三苯并[a,f,k]三茚（芳基分别为苯基和－萘基）,并通过从头算对其及其异构体的结构进行了分析,结果发现当芳基为苯基时,其顺式异构体分子印环中所有原子不完全处于共平面,而其反式异构体和1－萘基的顺反异构体均处于共平面。     

Quantum-chemical study of silacyclohexanes C5H10SiHCN, C5H10SiH(t-Bu), C5H10Si(t-Bu)CN, and C5H10SiHF

By quantum-chemical calculations at the M06-2X/aug-cc-pVTZ level of theory geometrical parameters, dipole moments, polarizabilities, first hyperpolarizabilities and relative energies of the axial and equatorial conformers in gaseous phase were determined for 1-cyano-1-silacyclohexane, 1-tert-butyl-1-silacyclohexane, 1-tert-butyl-1-cyano-1-silacyclohexane, and 1-fluoro-1-silacyclohexane. For the cyano group and fluorine atom the axial position is more preferable whereas for tert-butyl group, equatorial one. Polarizabilities of conformers are similar but optical anisotropy of equatorial conformers of C₅H₁₀SiHCN and C₅H₁₀SiH(t-Bu) molecules is much larger than that of axial conformers. Upon substitution in nitriles of C¹ atom by Si atom the hyperpolarizability is many times increased.     

2-羟基-1O,11-二氢-5H-二苯并[a,d]环庚烯-5-酮的合成

以2－羟基苯甲醛和3－甲氧基苯乙酸为原料,经3步反应合成2－羟基－10,11－二氢－5H－二苯并[a,d]环庚烯－5－酮。     

Conformations of the 10-membered Ring in 5, 10-Secosteroids. II. (E)-3α-Acetoxy-5, 10-seco-1 (10)-cholesten-5-one and (E)-5, 10-seco-1 (10)-cholestene-3, 5-dione

(E)-3α-Acetoxy-5, 10-seco-1(10)-cholesten-5-one ( 3 ) was synthesized by fragmentation of 3α-acetoxy-5α-cholestan-5-ol ( 1 ) using the photochemical version [3] of the lead tetraacetate reaction [4], and transformed into the corresponding 3-oxo-compound ( 5 ). Two conformations ( A and B ) were deduced for the 10-membered ring of 3 by analysis of the ¹H- and ¹³C-NMR. spectra in toluene. The major conformation ( A ) corresponds to that found in the solid state by X-ray analysis. According to its NMR. spectra in toluene, the medium-sized ring of the diketone 5 exists also predominantly in two conformations, the major one being analogous to A (the solid-state conformation of the 3β-acetoxy isomer ( 9 ) [1]) and the minor one to A (see above). The stereochemistry of the acidcatalyzed and thermal cyclisations of 3 as well as of the corresponding 5-oxime is discussed in terms of conformational factors.     

Nonplanar aromatic compounds. 5. A atrategy for the synthesis of cis-10b,10c-dimethyl-10b,10c-dihydropyrenes. First crystal structure of a cis-10b,10c-dimethyl-10b,10c-dihydropyrene.

Through the use of a potentially removable tether, a heavily substituted 10b,10c-dimethyl-10b,10c-dihydropyrene (DMDHP), 20, was synthesized exclusively as the cis-isomer. It exists as the major component (20:1) in an equilibrium with its valence isomer syn-[2.2]metacyclophanediene 19. An X-ray crystal structure determination of 20, a cis-(2,7)-10b,10c-dihydropyrenophane, provided the first experimental measurements of the cis-DMDHP skeleton. The observed bond alternation in the [14]annulene was found to be larger than that of the corresponding trans-DMDHP framework. Prior MMPI calculations, on which previous discussion of the structure of the cis-DMDHP system had been based, are in very good agreement with the experimental results. Our own DFT calculations predict a more symmetric and more bond equalized structure than was observed in 20.     

Tetracyclines Communication 33. Synthesis of 8-chloro-5-methoxy-3,10-dioxo-1,2,3,4,4a,9,9a,10-octahydroanthracene [5-chloro-1,3,4,4a,9a,10-hexahydro-8-methoxy-2,9-anthracenedione]

Summary 8-Chloro-5-methoxy-3,10-dioxo-1,2,3,4,4a,9,9a,10-octahydroanthracene (Ib) was synthesized; this can serve as an intermediary in the preparation of the tetracyclic analog (IIb) of aureomycin,Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 806–810, May, 1965 Original article submitted April 22, 1963For preceding communication see [1],The authors thank L. B. Senyavina for infrared spectrum measurements.     

An efficient catalytic method for the synthesis of 2,7-dialkyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrenes

An efficient method for the synthesis of 2,7-dialkyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrenes in high yields (up to 95%) via the intermolecular cyclization of 1,4,5,8-tetraazadecalin with N,N-bis(methoxymethyl)-N-alkylamines in the presence of SmCl₃·6H₂O as the catalyst has been developed.     

Ni5, Ni8, and Ni10 clusters with 2,6-diacetylpyridine-dioxime as a ligand

In the present work, novel coordination possibilities for the system dapdoH(2)/Ni(II) (dapdoH(2) = 2,6-diacetylpyridine-dioxime) have been explored. Depending on the starting reagents and solution conditions, several clusters with nuclearities ranging from Ni(5) to Ni(10) were achieved and structurally characterized, namely, [Ni(5)(R-COO)(2)(dapdo)(2)(dapdoH)(2)(N(CN)(2))(2)(MeOH)(2)] in which R-COO(-) = benzoate (1) or 3-chlorobenzoate (2), [Ni(8)(dapdo)(4)(NO(3))(4)(OH)(4)(MeOH)(4)] (3), and [Ni(10)(dapdo)(8)(N(CN)(2))(2)(MeO)(MeOH)](NO(3)) (4). For the first time, pentadentate coordination for the dapdo(2-) ligand has been established. All compounds show a combination of square-planar and octahedrally coordinated nickel atoms. According to the Ni(2)(sp)Ni(3)(Oh) (1 and 2), Ni(4)(sp)Ni(4)(Oh) (3), and Ni(4)(sp)Ni(6)(Oh) (4) environments, these systems magnetically behave as trimer, tetramer, and hexanuclear clusters, respectively. dc magnetic measurements in the 2-300 K range of temperature reveal antiferromagnetic coupling for all compounds, and the correlation of the superexchange interaction with the torsion angles involving the oximato bridges is experimentally confirmed.     

Stereoselective Syntheses of the Isomeric 5, 10-Pentadecadienals

The four isomeric 5, 10-pentadecadienals 1 , 2 , 3 and 4 were prepared by stereo-selective routes from acetylenic precursors. Two of them, 2 and 4 , were also made by Wittig reaction from 2-hydroxytetrahydropyran (29) . 2-Hydroxytetrahydropyran (29) yields (Z)-5-alkenols efficiently by Wittig reaction, and (Z)-4-hexenol was similarly made from 2-hydroxytetrahydrofuran (66) .     

NMR-spektroskopische Untersuchungen zur Thiolyse von Decachlorocyclopentaphosphazen,N5P5Cl10

NMR Spectroscopic Studies on the Thiolysis Reaction of Decachlorocyclopentaphosphazenen, N₅P₅Cl₁₀ A series of different but exclusively geminally substituted products, N₅P₅Cl_10?n(SR)_n, is formed by reactions of decachlorocyclopentaphosphazene, N₅P₅Cl₁₀, with sodium ethanethiolate, NaSEt, or benzenethiolate, NaSPh, in benzene or ether. The degree of substitution is low (mainly up to n = 4); intensified conditions do not result in further substitution but in decomposition. The compounds were separated by column chromatography and identified by ³¹P NMR spectroscopy. ³¹P chemical shifts and P—P coupling constants of the investigated compounds systematically change with the progressive substitution by SR groups. The chlorine-replacement pattern is discussed.     

Reactions of 5-Acetyl-10, 11-epoxy-10, 11-dihydro-5H-dibenz [b,f] Azepine with Alcohols and Trialkyl Orthoformates

The title compound (1) was reacted with trialkyl orthoformates and alcohols in the presence of boron trifluoride etherate. Depending on the solvent and temperature 10-acetyl-9-(dialkoxy)- methyl-9, 10-dihydroacridines(2) and/or 5-acetyl-10-alkoxy-11-hydroxy-10, 11-dihydro-5H-dibenz[b,f] azepines were formed (3).     

Efficient Catalytic Synthesis of 2,7-Diaryl(hetaryl)-4,9-dimethylperhydro- 2,3a,5a,7,8a,10a-hexaazapyrenes

A one-pot procedure has been developed for the synthesis of 2,7-diaryl(hetaryl)-4,9-dimethylperhydro- 2,3a,5a,7,8a,10a-hexaazapyrenes by cyclocondensation of aren(hetaren)amines with formaldehyde and 2,6-dimethyl-1,4,5,8-tetraazadecalin in the presence of YbCl₃ · 6 H₂O as catalyst.