吡啶高三蝶烯的合成

2-溴-4-甲基吡啶（1）经氯代和碘代反应合成了2-溴-4-碘甲基吡啶（3）,3和蒽酮（4）反应生成10,10-二（2-溴-4-吡啶甲基）-9（10H）蒽酮（5）,5在3 MPa下与NaOCH3反应得到10,10-二（2-甲氧基-4-吡啶甲基）-9（10H）蒽酮（6）,6经硼氢化钠还原得到蒽醇（7）,7在对甲苯磺酸催化...     

蒽酮高分子复合物发光体的光老化研究

通过５５５ｎｍ单色光照射下的２小时人工老化和露天中２６个月自然老化。研究了蒽酮高分子复合物发光体的光老化性质，经过２６个月的自然老化发光峰值强度下降了４８％，树脂的光透过度下降了４０％，表明光老化的原因主要是树脂老化引起的。     

On the synthesis of hypericin by oxidative trimethylemodin anthrone and emodin anthrone dimerization: Isohypericin

Summary The base catalyzed oxidative dimerization of emodin anthrone exclusively yields hypericin. However, on oxidative dimerization of trimethylemodinanthrone a mixture of hexamethylhypericin and hexamethylisohypericin was obtained. Chromatographic separation of the hexabenzoyl derivatives was achieved, and by saponification about equal amounts of hypericin and isohypericrin were produced. Isohypericin could be characterized for the first time by its spectroscopic data and its protonation and deprotonationpK _a andpK _a ^* values.

---

Zur Synthese von Hypericin durch oxidative Dimerisierung von Trimethylemodinanthron und Emodinanthron: Isohypericin

Zusammenfassung Die basenkatalysierte oxidative Dimerisierung von Emodinanthron liefert ausschließlich Hypericin. Oxidative Dimerisierung von Trimethylemodinanthron ergibt jedoch ein Gemisch von Hexamethylhypericin und Hexamethylisohypericin. Die Hexabenzoylderivate wurden chromatographisch getrennt, und Hypericin und Isohypericin konnten aus diesen Derivaten durch Verseifung freigesetzt werden. Isohypercin konnte erstmals durch seine spektroskopischen Daten und seine Protonierungs- und Deprotonierungs-pK _aundpK _a ^* -Werte charakterisiert werden.

     

Crystal Structure of 10-(2'''',5''''-Dimethoxybenzylidene) Anthrone

1 INTRODUCTION The 10-benzylidene anthrones which are important intermediate for organic syntheses[1～3] usually possess thermochromism[4] and photo- chromism[5], and have been found recently to have evident anti-cancer activity[6]. We found that the substituents in the phenyl ring will affect the bioactivity of those compounds. For more deeply investigating the structure-activity relationships (SAR) and understanding interactions between the three dimensional structure of the compound …     

A stochastic cellular automata model of tautomer equilibria

ABSTRACT

Many chemical substances, including drugs and biomolecules, exist in solution not as a single species, but as a collection of tautomers and related species. Importantly, each of these species is an independent compoundwith its own specific biochemical and physicochemical properties. The species interconvert in a dynamic and often complicated manner, making modelling the overall species composition difficult. Agent-based cellular automata models are uniquely suited to meet this challenge, allowing the equilibria to be simulated using simple rulesand at the same time capturing the inherent stochasticity of the natural phenomenon. In the present example a stochastic cellular automata model is employed to simulate the tautomer equilibria of 9-anthrone and 9-anthrol in the presence of their common anion. The observed K_E of the 9-anthrone ? 9-anthrol tautomerisation along with the measured tautomer pK_a values were used to model the equilibria at pH values 4, 7 and 10. At pH 4 and 7, the anthrone comprises >99% of the total species population, while at pH 10the anthrone and the anion each represent just under half of the total population. The advantages of the cellular automata approach over the customary coupled differential equation approach are discussed.     

A New 10—Hydroxyl Anthrone Glycoside from Cassia Siamea Lam.

A new 10-hydroxyl anthrone glycoside,1,8,10-trihydroxyl-1-O-β-D-glucopyranosyl-3-methyl-10-C(S)-β-D-glucopyranosyl-anthrone-9 1 was isolated from the stem of Cassia siamea Lam. The structure was elucidated by spectral evidences, especially by 2D techniques.     

Synthesis and crystal structure of 7,7,10-trimethyl-7-silabenzo[a]anthrone

Skeletal isomerization of arylsilanes that occurs under conditions of catalytic dehydrocyclization and is accompanied by migration of the triorganosilyl group was additionally confirmed by dehydrocyclization of dimethyl(2,4-dimethylphenyl)(1-naphthyl)silane on chromium-containing oxide catalysts. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2236–2239, December, 1997.     

5,12-环氧-1,2,3,4,5,12-六氢-2-并四苯基甲基酮的合成研究

蒽环类抗生素是近年来颇受人们注意的抗肿瘤药物。其配糖体蒽环酮的化学合成也引起了有机化学工作者极大的兴趣。本工作报道了蒽环酮的重要前体——b,12-环氧-1,2,3,4,5,12-六氢-2-并四苯基甲基酮(1)的合成。 1是以2,3,5,6-四甲     

The absolute axial configurations of knipholone and knipholone anthrone by TDDFT and DFT/MRCI CD calculations: a revision

Triggered by a seemingly inconsistent twisting direction in the atroposelective ring cleavage reaction of biaryl lactones by using the ‘lactone concept’, the absolute axial configurations of the most important phenylanthraquinones, knipholone (1), and knipholone anthrone (2) were reassigned on the basis of renewed quantum chemical circular dichroism (CD) calculations using advanced, higher-level methods, viz. a time-dependent DFT (TDDFT) and a multireference configurational interaction approach (DFT/MRCI). Additional confirmation of the new configurational assignment of 1 and 2 was achieved by their stereochemically unambiguous interconversion, and further corroborated by the transformation of 1 into an ‘leuco’ phenylanthracene derivative 3, i.e., a compound with a substantially different chromophore, whose absolute configuration was independently assigned again by quantum chemical CD calculations. Accordingly, the dextrorotatory enantiomer of knipholone, (+)-1, and its anthrone, (+)-2, has the P-configuration, while the laevorotatory forms, (−)-1 and (−)-2 (which likewise exist in nature), are M-configured. From this new configurational assignment, the absolute axial stereostructures of a whole series of further naturally occurring phenylanthraquinones may now be deduced.