The Synthesis of 1,2-Diarylpropane-1,3-Diols via the Ivanoff Reaction

Abstract

The synthesis of two β-1 lignol dimers, 1,2-bis-(4-hydroxy-3-methoxyphenyl)-i,3-propanediol (Via) and l-(3-ethoxy-4-hydroxyphenyl)-2-(4-hydroxy-3-methoxyphenyl)-1,3-propanediol (VIb) was performed using the Ivan off Reaction in the key synthetic step. The erythro forms of Via and b were isolated as crystalline solids in yields of approximately 15%, while the threo isomers were obtained as oils. The ratio of threo: erythro isomers was approximately 3:1.     

Reaction of Terminal and Non-terminal Dihydroxy Fatty Acids with Hydrogen Bromide

The action of hydrogen bromide on non-terminal glycol acids (threo and erythro-6,7-dihydroxystearic acids) leads to the formation of 6(7)–7(6)-bromoacetoxystearic and 6(7)-ketostearic acids as major and minor products of the reaction. On the other hand the same reaction on a terminal glycol acid, 10,11-dihydroxyundecanoic yielded only one bromoacetoxy acid (10-acetoxy-11-bromoundecanoic) and a diacetoxy derivative (10,11-diacetoxyundecanoic) as minor and major products. Assignment of configuration and structures of reaction products are based on the I. R., N. M. R. and mass spectral studies. It is evident that hydrogen bromide reaction of the terminal glycol acid takes a different course from that observed in the nonterminal dihydroxy acids.     

Acetals and ethers. XII. Reaction Products of Prop-2-enal with 1,2- and 1,3-Diols

2-(Hydroxyalkoxyethyl)-substituted cyclic acetals ( 1; 2; 3a-3d; 4a-4d ), derivatives of 1, 3-dioxolane or 1, 3-dioxane have been obtained in a p-toluenesulphonic acid-catalysed reaction of prop-2-enal with an excess of ethylene, propylene-1, 2, trimethylene, or butylene-1, 3 glycol. Respective 2-vinyl-1, 3-dioxolanes or 2-vinyl-1, 3-dioxanes were the intermediate products. The products of the reaction involving propylene-1, 2 and butylene-1, 3 glycols were mixtures of cis- and trans-2, 4-disubstituted-1, 3-dioxolanes and cis- and trans-2, 4-disubstituted-1, 3-dioxanes. The structure of HOROCH₂CH₂- substituents at C-2 atom of 1, 3-dioxacyclane ring has been proved through 2, 4-dinitrophenylhydrazone derivatives of the corresponding aldehydes HOROCH₂CH₂CHO that, however, could not be isolated as individual compounds.     

Absolute Stereochemistry of 1,2-Diols from Lipids of Thermomicrobia

1,2‐Diol based phospholipids are a well‐known feature of bacteria from the class Thermomicrobia. Since these bacteria contain only lipids with an alkyldiol‐1 ‐phosphate backbone instead of sn‐glycero‐3‐phosphate, it is important to elucidate the stereochemistry of the 1,2‐diols. We have studied the absolute stereochemistry of long‐chain 1,2‐diols isolated from Thermorudis pharmacophila (formerly known as Thermomicrobia sp. WKT50.2) by nuclear magnetic resonance (NMR) using α‐methoxyphenylacetic acid (MPA). Low‐temperature (?60 °C) NMR of bis‐(R)‐MPA ester showed (R) stereochemistry of the 1,2‐diols. This is the first report concerning the stereochemistry of natural 1,2‐diols, which replace the glyceride moiety in phospholipids. The (R) stereochemistry of the diols is expected as it is the same configuration as for the common bacterial lipid backbone—sn‐glycero‐3‐phosphate. This is the first application of low‐temperature NMR of a single MPA derivative for assignment of stereochemistry of natural 1,2‐diols. The results were confirmed by the comparison of NMR data with bis‐(R)‐MPA ester of (R) and rac‐1,2‐octanediol.     

Oxidative Cleavage of Long Chain Olefins to Carboxylic Acids with Hydrogen Peroxide

The role of phase-transfer catalysts (PTC) (ammonium and phosphonium salts) with various anions on the biphasic oxidative cleavage of long chain olefins with aqueous hydrogen peroxide catalyzed by Na₂WO₄/H₃PO₄/PTC system has been investigated. It was shown that the nature of PTC widely affects the catalytic activity of the above system in the conversion of alkenes, cycloalkenes and unsaturated fatty acids into carboxylic acids.

     

Oxidative Cleavage of Long Chain Olefins to Carboxylic Acids with Hydrogen Peroxide

The role of phase-transfer catalysts (PTC) (ammonium and phosphonium salts) with various anions on the biphasic oxidative cleavage of long chain olefins with aqueous hydrogen peroxide catalyzed by Na₂WO₄/H₃PO₄/PTC system has been investigated. It was shown that the nature of PTC widely affects the catalytic activity of the above system in the conversion of alkenes, cycloalkenes and unsaturated fatty acids into carboxylic acids.     

Glycidols Esters, 2-Chloropropane-1,3-Diols,and 3-Chloropropane-1,2-Diols Contents in Real Olive Oil Samples and their Relation with Diacylglycerols

A series of authentic virgin, refined, and mixtures of olive oils was analyzed for their content of 2-and 3-chloropropanediol (MCPD) esters expressed as 2−/3-MCPD, glycidol (and related glycidyl esters) (GE), and diglycerides (DAG). High concentrations of MCPD and GE were found, above all, in pomace oils, which come from the poorer starting raw materials, while virgin olive oils, as expected, do not contain any process contaminant. On the other hand, DAGs are present in all samples, demonstrating that their involvement in the formation of such contaminants only occurs when temperatures are higher than that used during the refining steps. The lack of correlation between the amounts of MCPD and GE can be ascribed to their completely different chemical stability as the epoxy ring of the GE opens easily, leading to both short-chain derivatives and/or MCPD itself. This finding can also explain the data about the absence of 2-MCPD in all the analyzed oil samples: other than the statistical probability and the steric effect of the SN2 formation mechanism, both in favor of the 3- derivative, we have also to consider the MCPD formation pathway involving glycidol that, under opportune conditions of refining, can increase the whole amount of 3-MCPD (under thermodynamic control, 3-MCPD is more stable).     

离子液体催化苯与长链烯烃烷基化的连续反应性能

在强制混合-反应-分离-循环实验装置上考察了酸性氯铝酸盐室温离子液体[BMIM][AlCl4]催化苯与长链烯烃烷基化反应的连续操作、沿反应管侧线分布式连续进料和工业烯烃原料进料的连续反应性能。实验结果表明,即使在相对苛刻的反应条件下,纯烯烃原料1-十二烯单程转化率也能在反应器内达到100.0%,2-苯基异构体选择性高于37.7%。虽然侧线连续进料的位置不同,但在反应器出口前1-十二烯可完全转化。精制过的工业烯烃原料可以满足连续烷基化反应的要求。     

长链烷基改性苯基含氢硅油的制备与表征

围绕长链烷基改性苯基含氢硅油(DMPS)的制备与表征开展研究,以明确最佳工艺条件,并通过红外光谱和核磁共振氢谱确认其结构。     

Reaction and Coloration of Glasses with Hydrogen

The reaction of NBS 710 glass with hydrogen at 500°C and the resulting coloration of the glass have been studied using optical spectroscopy. Initially the reaction leads to the reduction of iron from ferrous to ferric state which subsequently combines with sulfur resulting in the formation of FeS. The origin of the color centers is proposed to be related to the formation of FeS.     

Reaction of Hydrogen with Optical Defects in Glasses

A kinetic model for the removal of optical defects in glasses by exposure to hydrogen or deuterium gas is presented. Since annealing involves a chemical reaction at low temperatures, it is called "chemical annealing" to distinguish it from the common, higher-temperature, thermal annealing processes. As an example, this model is applied to the elimination of the aluminum/oxygen hole center in irradiated vitreous silica at 73°C in 93 kPa of D₂.     

Derivatization of Keto Fatty Acids IV Reaction of Hydrazoic Acid on Long Chain Keto Acid Esters

In an attempt to synthesise acyclic tetrazoles the reaction of hydrazoic acid with long chain keto fatty acids was investigated. Reaction of methyl 10-oxoundecanoate with HN₃ for 24 hrs gave amide (IIb) and urea derivatives (III) while the same reaction for prolong period (four days) gave both amides (IIa and IIb). Similarly methyl 12-oxooctadecanoate (IV) gave an isomeric mixture of amide derivatives (Va and Vb). Other attempt to prepare tetrazole using sodium azide and catalytic amount of H₂SO₄ again gave the amide derivatives. Reaction in presence of large amount of methanol also gave amide derivative.     

固体酸对苯与烯烃烷基化反应的催化活性研究

对改性粘土类、固体超强酸ＺｒＯ２－ＳＯ４２－／ＳｉＯ２及改性Ｙ型分子筛三大类固体酸催化剂进行了比表面、孔径分布测定及正丁胺－ＴＰＤ表征，评价了它们对苯与烯烃烷基化反应的催化性能，并对催化活性的改性Ｙ型分子筛Ｓｒｌａｙ催化剂进行了失活与再生实验。     

Reaction of Silicate Glasses and Mullite with Hydrogen Gas

The increasing order of corrosion resistance to H₂ gas flowing fast enough to ensure that the reaction is the slow step is fused silica, aluminosilicate glass, and mullite at T =1300° to 1500° C; the activation energies are 347.3, 358.6, and 389.1 kj/mol (83.0, 85.7, and 93.0 kcal/mol), respectively. No detectable reaction with a-Al₂O₃ was observed. Addition of a small amount of CaO to the glass reduced its activation energy (283.7 kj/mol (67.8 kcal/mol)) and made its reactivity with H₂ similar to that of mullite at high temperatures. The reaction product for the glasses consisted of a porous zone composed of an intermediate layer close to mullite in composition and an outer layer of a-AI₂O₃. The reaction product for mullite consisted of a porous a-Al₂O₃ residue layer.     

Limiting Phenomena in the Reaction of Fluorine with Hydrogen

Reactions involving energy branching and deceleration by the end product were studied using as an example the reaction of fluorine with hydrogen. It has been shown that for such reactions, entrance into the autoignition region determined by static conditions (reagent concentration, pressure, and temperature) due to variation in the pressure of the mixture may be or may not be accompanied by mixture autoignition. The parameter determining the behavior of a particular mixture is the rate of variation in the mixture pressure. A process of fast (in the range of seconds) preparation of fluorocarbon mixtures with minimal yield of hydrogen fluoride is substantiated.     

Flash Photolysis of Hydrogen Peroxide I: The Reaction of Ozonide with Hydrogen Peroxide

The photochemistry of basic aqueous solutions containing hydrogen peroxide and oxygen has been investigated by the flash photolysis method. The decay of O₃^? was followed at 4300 Å over the pH range 13 – 13.7 as a function of hydrogen peroxide and oxygen concentrations. The decay was found to be of the first order under all conditions ?[d(O₃)^?/dt] = k_obs[O₃^?]. The pseudo first-order rate constant k^obs was found to be dependent on H₂O₂ and O₂ concentrations. A mechanism which is consistent with the experimental results is suggested.     

四丁基溴化铵催化过氧化氢氧化香紫苏醇合成香紫苏内酯的研究

在有机溶剂中,以质量分数30%过氧化氢作氧源,四丁基溴化铵为相转移催化剂,钨酸钠、硫酸氢钠为酸性催化剂,催化氧化香紫苏醇合成香紫苏内酯,考察了硫酸氢钠、钨酸钠、四丁基溴化铵用量和反应时间对反应的影响。当n（香紫苏醇）：n（双氧水）：n（四丁基溴化铵）：n（钨酸钠）：n（硫酸氢钠）=100：300：2：1：1,在回流温度下,反应6h,产率可达72%。     

长链烯烃的应用

概述了长链烯烃的生产工艺,石蜡裂解和低碳烯烃齐聚。详述了长链烯烃的应用,可生产烯烃共聚体、润滑油、表面活性剂、油田化学品等。通过对它们需求量和生产能力数据进行分析,得出国内外对长链烯烃需求量日益增大,开发生产长链烯烃具有重要意义。