24-亚甲基胆甾-5-烯-3β,19-二醇的合成

从豆甾醇出发,通过10步反应,合成得到具有显著细胞毒活性的24-亚甲基胆甾-5-烯-3β,19-二醇(1),总产率为16%.目标产物1的熔点、[α]值和波谱数据与天然产物一致.化合物1的合成是首次报道,它对人体鼻咽癌(CN2)和胃癌(Mgc803)细胞有显著抑制活性.     

5α,11-二羟基-2-氧代桉烷-3-烯的全合成

5α，11-二羟基-2-氧代桉烷-3-(5α-Hydroxy—isopterocarpolone，1)是由贾忠建等于1996年从中药南牡蒿中首次分离得到的一种桉烷型倍半萜类天然产物．桉烷型倍半萜类化合物广泛分布于天然植物中，具有较好的昆虫拒食、抑制细胞繁殖和植物生长调节等多种生理活性．天然产物1的合成研究尚未见报道．     

5-丁基-9-苯基-4, 5, 6, 9-四氢苯并[d, e]恶唑[5, 4-g]-异喹啉-4, 6-二酮的合成

本文给出了一条较好的制备5-丁基-9-苯基-4, 5, 6, 9-四氢苯并[d, e]恶唑[5, 4-g]-异喹啉-4, 6-二酮的反应路线, 即: 先由4-溴-1, 8-萘酐经亚胺化、硝化、水解和还原等反应制得N-丁基-3-硝基-4-羟基-1, 8萘酰亚胺, 再在硼酸的存在下, 将亚胺与苯甲酰氯反应可得到目标化合物。文中给出了该化合物的质谱、核磁共振、红外、紫外和荧光等光谱数据。     

2’-脱氧腺苷-5’-磷酸与羟基自由基反应所形成的自由基

运用可靠的B3LYP/DZP++方法研究了2'-脱氧腺苷-5'-单磷酸(dAMP)与羟基自由基(HO·)的反应中所产生的20余种自由基. 结果表明, 反应的初始产物包括HO·加成到dAMP碱基C8、C4位上所形成的羟基加合物自由基, 以及dAMP碱基环上氨基的脱氢自由基. 而且,反应最初形成的C4位羟基加合物自由基具有脱水产生dAMP碱基环上氨基脱氢自由基的热力学趋势, 脱水形成的两种氨基脱氢自由基都是强氧化剂.尽管HO·加成到dAMP碱基C2位上所形成的加成产物比C4位的加成产物更稳定, 但dAMP与HO·的氧原子间较强的静电排斥作用却使得HO·难以靠近C2原子, 导致C2位的羟基加成产物难以形成. 上述结论不但与有关实验结果一致, 而且还对一些实验现象作出了合理的解释.     

5-氟-4-脱氧-β-L-尿苷的合成

L-核苷是天然核苷的对映异构体，虽然早在20世纪60年代就有人报道L-核苷的合成，但直到最近人们对它才开始重视．生物活性研究发现，在合成核苷和DNA的酶中，细胞脱氧胞苷激酶(deK)缺乏立体专一性，它可对一些核苷类如3TC，FTC和ddC的2个对映体同时磷酸化，细胞脱氧胞苷激酶不仅可活化胞嘧啶衍生物，而且可活化腺嘌呤类的2个对映体(如D-，L-ddA；D-，L-d4A)．     

新型阻燃剂1 ,3 ,5-三(5 ,5-二甲基-1 ,3-二氧杂己内磷酸酯基)苯的合成及表征

以1,3,5-三羟基苯、新戊二醇、三氯氧磷等为原料,采用简洁、高效的合成路线,通过两步反应合成了新型阻燃剂1,3,5-三(5,5-二甲基-1,3-二氧杂己内磷酸酯基)苯.通过红外光谱、核磁共振氢谱、质谱、元素分析以及热失重分析等对产物结构和热性能进行了表征和研究.热失重分析表明:该阻燃剂起始分解温度为295.26℃ ,在295.26℃ ~343.38℃和350.40℃ ~578.04℃温区迅速炭化;当阻燃剂被加热到681.03℃时,炭残余量高达43.33 %.     

新型螺[氧化吲哚-3,3′-吡唑]-5′-二氟甲基-4′-甲酸酯类化合物的合成

以原位生成的二氟甲基重氮甲烷（CF₂HCHN₂）与靛红衍生的3-烯基氧化吲哚为原料,通过[3+2]环加成反应和1,3-H迁移过程,合成了3种结构新型的螺[氧化吲哚 3,3′-吡唑]-5′-二氟甲基-4′-甲酸酯类化合物,收率41~68%, dr 91: 9~99 : 1,其结构经¹H NMR, ¹³C NMR, ¹⁹F NMR和HR-MS(ESI-TOF)表征。并通过单晶X-射线单晶衍射确定其相对构型。     

Acid?Base Properties of Adenosine 5′‐Monophosphate,Guanosine 5′‐Monophosphate,and Inosine 5′‐Monophosphate in Aqueous Solutions of Methanol

The protonation constants of adenosine 5′‐monophosphate, guanosine 5′‐monophosphate, and inosine 5′‐monophosphate were determined in binary mixtures of H₂O containing 0, 10, 15, 20, 25, 30, 35, 40, 45, and 50% MeOH, using a combination of potentiometric and spectrophotometric methods at a constant temperature (25°) and constant ionic strength (0.1 mol?dm^?3 NaClO₄). The protonation constants were analyzed using the normalized polarity parameter (E ), and Kamlet, Abboud, and Taft (KAT) parameters. A linear correlation of log K vs. the normalized polarity parameter was obtained. Dual‐parameter correlation of log K vs. π* (dipolarity/polarizability) and α (H‐bond‐donor acidity), as well as π* and β (H‐bond‐acceptor basicity) also gives good results in various aqueous organic solvent mixtures. Finally, the results are discussed in terms of the effect of solvent on the protonation equilibria.     

(4R,5S)-5-羟基-4-甲基-3-己酮的合成

农业害虫药材甲Stegobium panicem Linnae在我国各省区都有分布,主要危害谷类、食品、药材、图书、档案等.我国一般每年可以发2～3代,温度较高的地区可发生4代[1] .     

2, 3-二氯-5-取代-5, 8-二氢-8-氧-吡啶并[2, 3-b)吡嗪-7-羧酸乙酯的合成

3, 5, 6-哌嗪三酮-2-甲酰胺(5)经与PCl5-POCl3反应制得3, 5, 6-三氯-2-氰基吡嗪(6)。6经转化为甲酯(7)再水解为3, 5, 6-三氯-2-吡嗪甲酸(8)。由8出发合成了两个2, 3-二氯-5-取代-5, 8-二氢-8-氧-吡啶并[2, 3-b]吡嗪-7-羧酸乙酯(11a~b)。其中5, 7~11均为新化合物, 其组成和结构经元素分析、IR、^1H NMR、MS证实。     

5-雄烯-3β, 7α, 17β-三醇和5-雄烯-3β, 7β, 17β-三醇的合成

以5-雄烯二醇为原料,用微生物转化的方法合成了两个重要的神经甾体5-雄烯-3β, 7α, 17β-三醇和5-雄烯-3β, 7β, 17β-三醇。所用菌种总枝毛霉为我们自己筛选,并首次应用于5-雄烯-3β, 7α, 17β-三醇和5-雄烯-3β, 7β, 17β-三醇的合成中。     

Synthesis and Fungicidal Activities of 2-Alkylthio-5- （3, 4, 5-tribenzyloxyphenyl）-1, 3, 4-oxadiazoles

Abstract： Ten novel 2-alkylthio-5-（3, 4, 5-tribenzyloxyphenyl）-1, 3, 4-oxadiazole derivatives （5a-j） were synthesized from methyl 3, 4, 5-trihydroxybenzoate by ethedfication, hydrazidation, cyclization and thioetherification reactions. The structures of 5a-j were confirmed by 1HNMR, MS spectra and elemental analysis. The results indicated that most of the compounds 5 exhibited good fungicidal activities. The activity of 5h is higher than 90% against Fusarium oxysporum and Botrytis cinereapers in 50 mg/L.     

Bonding situation and stability of η1- and η6-bonded heteroarene complexes M(η1-EC5H5)6 and M(η6-EC5H5)2 (M = Cr,Mo, W; E = N,P, As,Sb, Bi)

Density functional calculations at the BP86/TZ2P level are reported for the pseudo-octahedral heteroarene complexes M(η¹-EC₅H₅)₆ and for the sandwich complexes M(η⁶-EC₅H₅)₂ (M = Cr, Mo, W; E = N, P, As, Sb, Bi). The complexes M(CO)₆ and M(η⁶-C₆H₆)₂ have been calculated for comparison. The nature of the metal–ligand interactions was analyzed with the EDA (energy decomposition analysis) method. The calculated bond dissociation energies (BDE) of M(η¹-EC₅H₅)₆ have the order for E = P > As > N > Sb ? Bi and for M = Cr < Mo < W. All hexaheteroarenes bind more weakly than CO in M(CO)₆. Except for pyridine, which is the weakest η⁶-bonded ligand, the trend in the BDE of the M(η⁶-EC₅H₅)₂ complexes is opposite to the trend of the M(η¹-EC₅H₅)₆ complexes NC₅H₅ < PC₅H₅ < AsC₅H₅ < SbC₅H₅ < BiC₅H₅. The opposite trend is explained with the different binding modes in M(η⁶-EC₅H₅)₂ and M(η¹-EC₅H₅)₆. The bonding in the former complexes mainly takes place through the π electrons of the ligand which are delocalized over the ring atoms while the bonding in the latter takes place through the lone-pair electrons of the heteroatoms E. The Lewis basicity of the group-15 heterobenzenes EC₅H₅ becomes weaker for the heavier elements E. The occupied π orbitals of the heterobenzene ring become gradually more polarized toward the five carbon atoms in the heavier arenes EC₅H₅ which induces stronger metal-carbon bonds in M(η⁶-EC₅H₅)₂ and weaker metal-E bonds. The EDA calculations show that the nature of the M-EC₅H₅ bonding in M(η¹-EC₅H₅)₆ is similar to the M–CO bonding in M(CO)₆. Both types of bonds have a slightly more covalent than electrostatic character. The π orbital interactions in the chromium and molybdenum complexes of CO and heterobenzene are more important than the σ interactions. This holds true also for the tungsten complexes of CO and the lighter heteroarenes while the σ- and π-bonding in the heavier W(η¹-EC₅H₅)₆ species have similar strength. The EDA results also show that the nature of the bonding in the sandwich complexes M(η⁶-EC₅H₅)₂ is very similar to the bonding in the bisbenzene complexes M(η⁶-C₆H₆)₂. The orbital interactions contribute for all metals and all arene ligands about 60% of the attractive interactions while the electrostatic attraction contributes about 40%. The largest contribution to the orbital term comes always from the δ orbitals. The calculations predict that the relative stability of the sandwich complexes M(η⁶-EC₅H₅)₂ over the octahedral species M(η¹-EC₅H₅)₆ increases when E becomes heavier and it increases from W to Mo to Cr when E = N, P, As.     

3, 5-二氯苯胺的电化学合成

以3, 5-二氯硝基苯为原料, 采用阴极转动分隔式电解槽, 在65℃、电流密度10A/dm^2、阴极转速400r/min和电极电位在-0.35～-0.45V范围的条件下进行电合成, 所得3, 5-二氯苯胺的产率达90%左右, m.p. 49～52℃。     

6α-取代的(1S, 7aS)-(+)-1-叔丁氧基-7a-甲基-2, 3, 5, 6, 7, 7a-六氢茚-5- 酮的合成

用化学动力学控制的方法在化合物3的5-C上C=O与6-C发生烯醇化生成锂盐,然后可在6-C位分别引入甲基、烯丙基、苄基、溴以及羟基取代基。产物6、7、8、9a和11经鉴定,除9α外其他都是α和β构型的混合物,其中以α-构型取代物为主。     

6α-取代的(1S, 7aS)-(+)-1-叔丁氧基-7a-甲基-2, 3, 5, 6, 7, 7a-六氢茚-5- 酮的合成

用化学动力学控制的方法在化合物3的5-C上C=O与6-C发生烯醇化生成锂盐,然后可在6-C位分别引入甲基、烯丙基、苄基、溴以及羟基取代基.产物6、7、8、9a和11经鉴定,除9a外其他都是α和β构型的混合物,其中以α构型取代物为主.     

微波炉加热法合成3-芳基-1, 2, 4-三唑啉-5-硫酮

本文报道了微波炉加热法合成3-芳基-1, 2, 4-三唑啉-5-硫酮,研究了反应时间, 溶液用量, 微波功率及芳基对反应产物收率的影响。     

An Interplay of Cooperativity between Cation⋅⋅⋅π, Anion⋅⋅⋅π and C?H⋅⋅⋅Anion Interactions

Mixed cation (Li⁺, Na⁺ and K⁺) and anion (F^?, Cl^?, Br^?) complexes of the aromatic π‐surfaces (top and bottom) are studied by using dispersion‐corrected density functional theory. The selectivity of the aromatic surface to interact with a cation or an anion can be tuned and even reversed by the electron‐donating/electron‐accepting nature of the side groups. The presence of a methyl group in the ? OCH₃, ? SCH₃, ? OC₂H₅ in the side groups of the aromatic ring leads to further cooperative stabilization of the otherwise unstable/weakly stable anion???π complexes by bending of the side groups towards the anion to facilitate C? H???anion interactions. The cooperativity among the interactions is found to be as large as 100 kcal mol^?1 quantified by dissection of the three individual forces from the total interaction energy. The crystal structures of the fluoride binding tripodal and hexapodal ligands provide experimental evidence for such cooperative interactions.     

Synthesis and steric structure of 2-[1-(3-chlorophenyl)-2,2,2-trifluoroethoxy]-3-(trichloromethyl)-6,7-benzo-1,4,2λ<Superscript>5</Superscript>-dioxaphosphepin-5-one 2-oxide

The reaction with chloral of 2-[1-(3-chlorophenyl)-2,2,2-trifluoroethoxy]-5,6-benzo-1,3,2-dioxaphosphorinan-4-one containing a chiral fluorinated exocyclic substituent on phosphorus leads to formation of 2-[1-(3-chlorophenyl)-2,2,2-trifluoroethoxy]-3-(trichloromethyl)-6,7-benzo-1,4,2⁵-dioxaphosphepin-5-one 2-oxide with a high regio- and stereoselectivity. The molecular and supramolecular structure of the isolated diastereomer was established by means of X-ray diffraction.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 12, 2004, pp. 1973–1980.Original Russian Text Copyright © 2004 by Gubaidullin, Burnaeva, Mironov, Litvinov, Kotorova, Ivkova, Goryunov, Konovalova, Mastryukova.This revised version was published online in April 2005 with a corrected cover date.