松节油及α-蒎烯和β-蒎烯的臭氧化反应

松节油的主要成分是 α-蒎烯和 β-蒎烯 ,经臭氧化反应后分别生成蒎酮醛和诺蒎酮的前提化合物 [1] ,它们是合成珍贵香料鸢尾酮和 4-异丙基环己酮衍生物等香料的中间体 .α-蒎烯和 β-蒎烯在气相中的臭氧化反应动力学 [2 ]和 β-蒎烯的液相臭氧化反应 [3]已有研究 ,但 α-蒎烯和 β-蒎烯混合物以及松节油在溶液中的臭氧化反应选择性未受到关注 ,影响了松节油的直接臭氧化深加工利用 .采用松节油直接臭氧化是降低由 α-蒎烯合成鸢尾酮成本的重要途径 .本文通过 α-蒎烯和 β-蒎烯二元混合物及松节油在乙醇中的臭氧化反应的实时反应物浓度分析 …     

α—蒎烯异构成β—蒎烯的一个简便方法

β-蒎烯是一个重要的有机合成原料,但我国松节油中的β-蒎烯含量甚少,主要为α-蒎烯·将α-蒎烯异构化成为β-衍生物已有许多报道。本文将三乙基硼氨合物或三乙基苄基铵合硼烷使之与α-蒎烯反应成二(3-蒎烷基)硼烷,再经热异构重排成二(10-蒎烷基)硼烷,最后与双戊烯进行置换反应,顺利地制得了β-蒎烯。与Brown的方法相比,本法简便、安全,并且用我国合成樟脑生产中的副产物双戊烯代替了十二烯-(1)。     

α-蒎烯/β-蒎烯共聚物合成与表征

α-蒎烯/β-蒎烯共聚物合成与表征;松节油;α-蒎烯;萜烯树脂;阳离子聚合     

用于烯蒎气相加氢反应的分子筛催化剂

<正> 前言蒎烷是松节油的主要成份蒎烯经加氢而得,目前生产上多以Raney镍为催化剂,用高压釜进行液相加氢来生产蒎烷。为了实现加氢过程连续化,我们研究了适用于固定床的蒎烯气相加氢催化剂。由于蒎烷是医药、合成橡胶引发剂,特别是合成香料重要的中间体,因此对于蒎烯加氢催化剂早有研究,近年来有关α-蒎烯选择氢化为顺式蒎烷的报导较多。目前在萜类化学上利用沸石分子筛的实例还很少,如有用于α-蒎烯和β-蒎烯的分离,也有     

火炬松挥发物的固相微萃取-气相色谱/质谱法分析

采用固相微萃取(SPME)技术,结合气相色谱/质谱(GC-MS)分析了火炬松枝条和针叶中的挥发性化合物,共鉴定了30种化学成分。其中枝条中分离鉴定出21种挥发性成分。主要成分为α-蒎烯、β-蒎烯、β-月蒎烯、反式-石竹烯、β-杜松烯、大根叶烯-D;针叶中分离鉴定出24种挥发性成分,主要成分为α-蒎烯、β-蒎烯、β-月桂烯、β-水芹烯、异长叶烯、反式-石竹烯、α-律草烯、大根叶烯-D、双环吉马烯和双环榄香烯。     

马尾松、湿地松、油松针叶挥发物中手性单萜的组成与相对含量

采用动态顶空吸附／手性毛细管气相色潜-质谱（GC—MS）法，首次分析研究了马尾松（Pinus massoniana Lamb）、湿地松（Pinus elliottii Engelm）、油松（Pinus tabulaeformis Carr．）针叶挥发性化合物中主要手性单萜（α-蒎烯、莰烯、β-蒎烯、β-水芹烯、柠檬烯）的组成与相对含量，结果表明其在种间相差较大。马尾松中的（-）-α-蒎烯的含量（55．50％）最高，而其对映异构体（＋）-α／-蒎烯在油松中含量（16．86％）最高，（-）β-蒎烯在湿地松中含量（43．38％）最高。马尾松手性单萜的组成和含量在树与树间差异也较大。     

乙酰丙酮氧钒催化氧化α-蒎烯一步转化成龙脑烯醛

以乙酰丙酮氧钒为催化剂,过氧化氢为氧化剂,研究了由α-蒎烯直接合成龙脑烯醛的反应。考察了溶剂、温度、催化剂用量、反应时间等因素对催化性能的影响。结果表明,乙酰丙酮氧钒与H2O2反应得到的高价态V5+是优良的氧化还原-Lewis酸双功能催化剂,易使α-蒎烯经氧化、2,3-环氧蒎烷异构得到龙脑烯醛。在n(H2O2):n(α-蒎烯):n(乙酰丙酮氧钒)=2.5:1:0.01、反应温度为20℃、丙酮为溶剂、反应2h条件下,α-蒎烯转化率为50.2%,龙脑烯醛的选择性达58.7%,反应6h后α-蒎烯转化率可达73.0%,主要产物龙脑烯醛和马鞭草烯酮的选择性分别为47.2%和13.2%。     

水促进的氯化钌催化α-蒎烯加氢反应

考察了水促进的RuCl3催化α-蒎烯加氢反应.结果表明,同传统催化剂或无水RuCl3相比,水对α-蒎烯加氢反应具有明显的促进作用,可显著提高蒎烷选择性及产物中蒎烷顺反比,且容易实现产物的分离及催化剂的循环使用.在RuCl3·3H2O用量1.8mg,α-蒎烯2.5g,m(H2O):m(a-蒎烯)=4:1下,160℃,5M...     

α-和β-蒎烯蒸发焓的测定

松节油是我国的一大资源,它的主要组份是α-蒎烯和β-蒎烯,这两种化合物均为合成香料、医药和萜烯树脂等的重要化工原料,它们的分离和转化常常需要准确的化学热力学数据。由于文献中这些数据不全或准确性较差,有必要进行新的测定.本文报导了α-和β-蒎烯蒸发焓的测定结果。实验部分1.样品α-和β-蒎烯是从松节油中经分离制得的产品,由中山大学化学系提供,并进一步用Per-     

光催化下(-)-马鞭烯酮的重排

( )-马鞭烯酮[( )-Verbenone]是Wender研究组全合成紫杉醇(Taxol)的重要起始物．( )-马鞭烯酮可由( )-α-蒎烯在Co(Ⅱ)催化下氧化得到,并且在光照下重排得到( )-菊花烯酮[( )-Chrysanthenone]．但从( )-α-蒎烯到( )-菊花烯酮的总产率较低,约为16．5％．我们在重复由光活性α-蒎烯出发经过光活性马鞭烯酮及菊花烯酮衍生物合成紫杉醇AB环的实验中发现,由α-蒎烯合     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.