土木香内酯和异土木香内酯与共轭二烯的Diels-Alder反应

本文以土木香根中分离得到的土木香内酯(1)和异土木香内酯(2)为原料,分别与环戊二烯(3)、螺[2·4]-4,6-庚二烯(4)、呋喃、蒽或丙烯醛进行Diels-Alder反应,发现1和2只与3或4发生反应,未能得到1和2与呋喃、蒽或丙烯醛的反应产物.X射线单晶衍射法确定1或2与3的反应产物的构型.应用高分辨核磁共振谱NOE方法确定1或2与4的反应产物的构型.     

呋喃碳苷衍生物的合成及主产物构型的确认

在三氯氧磷催化下将2-甲基-5-(2′-氯-2′-脱氧-D-半乳糖-1-丁醇基)-3-乙酰基呋喃经脱水反应得到呋喃碳苷衍生物(2-甲基-5-[(4′-α-羟基-3′-β-氯)-2′-四氢呋喃基]-3-乙酰基呋喃),并对反应机理进行了讨论.通过2D NMR图谱确认了主产物的构型为α构型.     

菊花烯酮的合成及其Baeyer-Villiger反应

菊花烯酮(Chrysanthenone,2)与其环内酯(1actone,3)以及环内酯3的开环产物4是构成手性药物的重要中间体,本文由马鞭烯酮(Verbenone,1)经光化反应合成得到菊花烯酮(2),菊花烯酮经由Baeyer-Villiger反应得到了主要氧化产物3,对化合物3以1H NMR确定其结构的基础上,又以化学法探讨了构型.3开环得到了4,4再扣环得到了环内酯3,证明化合物4中的羟基(OH)和羧基(COOH)位于六元环的同侧.其反应如下:     

含三氟甲基的螺[环丙烷-1,3'-吲哚啉]-2'-酮和螺[环丙烷-1,2'-茚]-1',3'-二酮衍生物的高立体选择性简易合成

采用3-(4-三氟甲基苯亚甲基)吲哚啉-2-酮和2-(4-三氟甲基苯亚甲基)-1H-茚-1,3(2H)-二酮分别与鉮盐在二氯甲烷中,碳酸钾或氟化钾存在下反应,可高产率、高立体选择性地得到以反式构型为主的含三氟甲基的3'-螺环丙基取代的氧化吲哚和2'-螺环丙基取代的茚二酮衍生物.产物相对构型经X射线单晶衍射或1H-1H NOESY谱确定.还从反应机理的角度对产物构型做了解释.     

对映体纯1-甲基-7-氧杂双环[2.2.1]庚烷-2-酮的制备

1-甲基 - 7-氧杂双环 [2 .2 .1 ]庚烷 - 2 -酮 ( 1 )是萜类天然产物全合成中的重要中间体 ,能被广泛地应用于多种桉烷 ( Eudesmane)、沉香呋喃 ( Agarofuran)和降胡萝卜素 ( Norcarotenoids)等倍半萜天然产物的全合成[1,2 ] .我们以对映体纯化合物 1为原料 ,实现这类天然产物的不对称全合成 [3～ 6 ] .消旋的化合物 (± ) - 1可以 2 -甲基呋喃和 2 -氯丙烯腈为原料 ,经 3步反应得到 [2 ] .但对映体纯化合物 1的制备尚未见报道 .本文用化学拆分方法 ,成功地制备了对映体纯的 ( + ) - 1和 ( - ) - 1 ,并确定了其绝对构型 .1　结果与讨论为减…     

青蒿素及其一类物结构和合成的研究XIV.6-异脱氧双氢青蒿乙素的内酯构型和反应

根据圆二色谱和化学反应确定6的内酯构型为β-顺式,6用Pd-CaCO3或NaBH4-NiCl2还原时发生SN2'反应而得烯酸10。     

固体^1^3C NMR研究呋喃醇和呋喃醇与三-(2-羟乙基)-异氰酸尿酯缩聚磺化反应

用固体^1^3C NMR研究了呋喃醇(FA)和FA与三-(2-羟乙基)-异氰酸尿酯(THEIC)缩聚磺化反应及其产物结构, 考察了2-甲基呋喃封端的FA线型齐聚物与甲醛水溶液在相转移催化剂(C~4H~9)~4N^+I^-和与大量硫酸作用下的反应特点, 探讨了主要参数对反应的影响。阐明了缩聚交联磺化反应的规律, 确定了产物的结构。     

膦、胂叶立德的化学与应用ⅩⅩⅥ.含全氟烷基胂叶立德的合成及水解反应研究

报道溴化(α-呋喃甲酰基)甲基三苯基钟(1)在无水碳酸钾存在下,以无水二氯甲烷作溶剂,保持0～5℃下与2-全氟炔酸甲酯(2)反应,高产率地得到加合产物4-(α-呋喃甲酰基)-2-三苯基胂基-3-全氟烷基-3-丁烯酸甲酯(3).加合产物3在V(甲醇):V(水)=9:1溶液中分别于室温、回流和封管120℃三种条件下反应,高产率地得到4-全氟烷基-6-(α-呋喃基)-2-吡喃酮(4)和4-(α-呋喃甲酰基)-3-全氟烷基-3-丁烯酸甲酯(5).化合物4和5可以通过柱层析分离;化合物5为一对Z,E异构体,它们不能通过柱层析分离,但其比例可以由1HNMR估算得到.研究还发现硅胶对该反应具有催化作用,提出并讨论了反应机理.     

手性有机硅化合物 II.手性烯丙基硅烷与醛类化合物的不对称合成反应

由(-)-β-蒎烯合成了(-)-二甲基烯丙基(7,7-二甲基降蒎烷基)硅烷(1). 1和一系列醛反应可以得到手性高烯丙基醇(3). 反应有一定的对映异构体选择性. 产物的构型与使用的催化剂有关. 应用此反应合成了有光学活性的4-辛基-γ-内酯.     

12-(酰氧亚氨基)-1,15-十五内酯的合成及结构表征

以α-硝基环十二酮为原料,与丙烯醛加成、扩环并经Nef反应合成了12-氧代-1,15-十五内酯,再经成肟和酰化及硅胶柱层析分离分别得到12-(酰氧亚氨基)-1,15-十五内酯的顺式及反式异构体.结构经IR,¹HNMR及元素分析确证.通过对个别化合物的单晶X射线分析,结合¹HNMR数据,分别确定了它们的Z,E构型.结果表明,12-氧代-1,15-十五内酯成肟时对顺、反异构体的形成缺少明显的选择性,而目标化合物环骨架的优势构象为[23434],羰基和肟基位于两个不同的角碳位置.     

Selective detection of bismuth(III) and iron(II) ions with certain new reagents

Isoperthiocyanic acid (3-amino-5-thione-1,2,4-dithiazole) (I), tetraethylthiuram monosulphide ("Tetmosol") (II), eosin (III), and mercurochrome (IV) are used as new qualitative reagents for bismuth, III and IV are also used for detection of iron(II). A conc. sulphuric acid solution of I, or an acctone solution of II, when treated with bismuth in presence of potassium iodide, gives a deep red or reddish-orange precipitate, characteristic of bismuth. Bismuth in presence of III or IV gives a heavy and characteristically bright deeppink precipitate on addition of ammonia. With I, 1 mug of bismuth may be detected with a dilution limit of 1:50,000. Sb(III) and As(III) do not interfere in any of these tests. Iodides interfere only when I and II are used as reagents. Pb, Cu(II). and Fe(III) interfere with III and IV. I and II are also proposed as reagents for iodide; nitrites would interfere. III and IV, with iron(II) on addition of ammonia, produce a precipitate with highly intense green fluorescence. No other common cation [including Fe(III)] or anion interferes. The limit of detection is 3 mug ml .     

以硫醚为主链的螯合树脂研究Ⅳ．含硫代硫酸根、叠氮基树脂的合成及吸附性能

聚环硫氯丙烷或环硫氯丙烷与环氧氯丙烷共聚物，在少量二乙烯三胺存在下制得交联预聚物，将交联预聚物分别与硫代硫酸钠，叠氮化钠反应，制得四种侧链带有硫代硫酸根或叠氮基的新型螯合树脂。它们对贵金属离子具有较高的吸附容量和较好的吸附选择性。     

Ion flotation behaviour of thirty-one metal ions in mixed hydrochloric/nitric acid solutions

The ion flotation of 31 metal ions in hydrochloric/nitric acid solution with the cationic surfactant cetylpyridinium chloride was investigated. A 25-ml portion of 0.27-2.87 x 10(-4)M metal ion and 1.8-6.0 x 10(-4)M cetylpyridinium chloride solution in 0.17-3.4M acid mixture ([HCl]:[HNO(3)] = 2.4:1) was subjected to flotation in a cell, 22.5 cm high and 4.0 cm in diameter, for 5 min, with nitrogen bubbles. Ir(IV), Pt(IV), Ge(IV), Sn(IV), Bi(III), Au(III), Tl(III), Pd(II) and Sn(II) were floated from solution in 95-100% yield; Ru(III), Rh(III), Ir(III), Hg(II), Ag(I) and Tl(I) were partly floated, while Cr(VI), Ti(IV), Zr(IV), Ga(III), In(III), Fe(III), Sb(III), Al(III), Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), CD(II) and Pb(II) were floated with less than 20% yield. The flotation behaviour of these metal ions in the mixed acid system was compared with that in hydrochloric acid. The flotation is more efficient in the mixed acid system.     

Synthesis and Metal Collecting Properties of Mono,Di, Tri and Tetramine Based on Silica Gel Matrix

Abstract

Silica gels, chemically modified with mono, di, tri and tetramine (I - IV), were synthesized. The monoamine (I) was produced directly via the reaction of silica gel with 3-aminopropyltrimethoxysilane. The diamine (II), triamine (III) and tetramine (IV) were produced through the reaction of ethylenediamine (EDA), diethylenetriamine (DETA) and triethylenetetramine (TETA) with 3-chloropropyltrichloromethane modified silica gel, respectively. The sorption properties of the phases (I - IV) toward Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II) were investigated at different pH-values based on the batch equilibrium technique, The, metal uptake capacities (mmol/g) were determined and discussed in terms of the structure of the aliphatic amines and the increasing number of nitrogen donor atoms. The metal capacity values demonstrate the higher efficiency of phases III and IV than phases I and II for preconcentration of such metal ions. Moreover, the use of phases III and IV for selective extraction of Cu(II) and Ni(II) is promising.     

Electron transfer. 157. Reactions of hypervalent manganese species with S(2) metal-ion reductants

Solutions of the complexes of hypervalent manganese, [Mn(III)(C(2)O(4))(3)](3)(-) (in oxalate buffers), [Mn(IV)(bigH)(3)](4+) (in biguanide buffers), and [(bipy)(2)Mn(III)(O)(2)Mn(IV)(bipy)(2)](3+) (in bipyridyl buffers) may be reduced by s(2) center reductants In(I), Sn(II), and Ge(II), yielding Mn(II) quantitatively. In all cases, rates are determined by the initial act of electron transfer, giving an s(1) transient (In(II), Sn(III), or Ge(III)); subsequent steps are rapid and kinetically silent. The In(I)-Mn(III) and Ge(II)-Mn(III) reactions are inhibited by added oxalate, whereas the Sn(II)-(Mn(III)Mn(IV)) reaction is strongly accelerated by Cl(-). The In(I)-Mn(IV) reaction is complicated by formation of a 1:1 addition compound In(I).Mn(IV). We find no evidence for two-unit steps in any of these systems.     

Adsorption of metal ions on activated carbon from aqueous solutions at pH 1-13

Adsorption of microgram amounts of 20 metal species on activated carbon powder from aqueous solutions of pH 1-13 was investigated. The species examined were Cs(I), Y(III), Ce(III), Ti(IV), Zr(IV), Cr(III), Cr(VI), Mn(II), Fe(III), Co(II), Ni(II), Ru(III), Cu(II), Ag(I), Zn(II), Cd(II), Al(III), Pb(II), Sb(III) and Bi(III).     

以硫醚为主链的螯合树脂研究——Ⅲ.含硫氰酸根树脂的合成及吸附性能

环硫氯丙烷的均聚物或环硫氯丙烷与环氧氯丙烷的共聚物,在少量二乙烯三胺存在下制得预交联聚合物,将后者与硫氰化钾反应,制得两种侧链带有硫氰酸根的新型螯合树脂。它们对贵金属具有优良的吸附性能和高的吸附选择性。通过X射线光电予能谱初步探讨了树脂对金属离子的螯合作用     

Some derivatives of benzoin

Extension of the reaction time of benzoin (I) with anthranilamide (II) gave 2,3,5,6-tetraphenyl-pyrazine (IV) in addition to the expected benzamide III. Condensation of I with II in the presence of ammonium acetate or ammonium formate yielded IV, and IV with 4-quinazolinone (VII), respectively. Reaction of I with ammonium acetate only led to IV and 2,3,5,6-tetraphenylpyrrole (VIII). When I was heated with 2-aminothiazole, benzil, desoxybenzoin, and VIII were formed. A mechanism has been extended to explain the formation of IV and VIII.     

CNDO/2 molecular orbital calculations on the complexes formed between methyllithium and trimethylaluminium with aliphatic amines

Mono-(I), bis-(II), and tris-(triferrocenylphosphine)iron carbonyls (III) were obtained photochemically or thermally in high yields. The photochemical reaction of triferrocenylphosphine with iron pentacarbonyl was found to proceed only at elevated temperature, and it was discovered that I, first formed almost quantitatively, is converted to III by a disproportionation process. Complex II is not formed as an intermediate, notwithstanding the fact that II can be obtained by photochemically induced disproportion, as well as by thermally initiated substitution, from I as starting material. Several aspects of the reaction were explored, and a mechanism is suggested to account for the observed behavior. The product of the thermally initiated reaction of triferrocenylphosphine with butadieneiron tricarbonyl was characterized as a tris(phosphine)iron dicarbonyl (IV), structurally different from III. An examination of carbonyl stretching bands indicated that I and II are very probably trigonal bipyramidal in configuration with the phosphine ligand axially disposed. Consideration is given to possible structural configurations for III and IV.