Untersuchung zur Ringöffnungspolymerisation von 2-Phenoxymethyl-1,4,6-trioxa-spiro-[4,4]-nonan

Investigation of Ring-Opening Polymerization of 2-Phenoxymethyl-1,4,6-trioxa-spiro[4,4]-nonan Under the conditions of a radical induced cationic ringopening-polymerization the spiro ortho ester 1b can be polymerized with diphenyliodoniumtetrafluorborat/benzpinacol (1:1). The optimal initiator concentration is 2–2.5 mol-% Ph₂I⁺BF₄⁻. The average molecular weight is 6000, Tg = −4°C. Polymerization of 1b in presence of BF₃ · Et₂O produced identical results. The structure of polymer 2b was indicated by its analysis as well as its infrared spectra.     

Cycloadditionen von 6H-1,3,4-Oxadiazin-6-onen (4,5-Diaza-α-Pyronen). 14. Nicht katalysierte und durch Trifluoressigsäure katalysierte Reaktionen von 6H-1,3,4-Oxadiazin-6-onen mit Norbornen

Cycloadditions of 6H-1,3,4-Oxadiazin-6-ones (4,5-Diaza-α-pyrones). 14. Reactions of 6H-1,3,4-Oxadiazin-6-ones with Norbornene: Non-catalysed and Catalysed by Trifluoroacetic Acid In 11 out of 13 non-catalysed reactions of oxadiazinones 1 with norbornene, γ-oxoketenes 4 were observed and could be isolated in three cases ( 4b,d,m ). Except for 4m , all γ-oxoketenes isomerised to enollactones of type 5 on thermolysis. However, 4b furnished the cyclobutene derivative 10 as the major product. No γ-oxoketenes were detected in the reactions of 1k and 1l , which gave rise to the formation of 5k and the enollactone 19 , respectively. The latter was converted into 5l on treatment with trifluoroacetic acid (TFA). Four oxadiazinones 1 were allowed to react with norbornene in the presence of TFA. Three of them ( 1a,b,l ) afforded mixtures of enollactones of type 5 and their diastereomers 12 . Heating of 4 in the presence of norbornene led to the formation of the symmetrical δ-lactones 6. This process was observed to be efficient only where the conversion 4 → 5 is slow ( 4b ) or inoperative ( 4m ). In five cases, the treatment of the components with boron trifluoride etherate proved to be a useful preparative alternative ( 6a,d,g,h,m ). On treatment of 4a with methanol, the pseudoester 7a was formed, whereas 4b gave mixtures of 7b and the esters 8b and 15. Hydrogen chloride converted 4b into the pseudochloride 14 , which furnished pseudoester 7b on methanolysis. Reaction of 4b,m with formic acid gave rise to pseudoanhydrides of type 13. From 4b and TFA a mixture of the enollactones 5b and 12b was obtained. Boron trifluoride etherate transformed 4i to enollactone 12i ; analogously, 12m resulted on treatment of 4m with trifluoromethanesulfonic acid.     

Zweifache Ringöffnung von 2,3,5,6-Tetrahydro-10bH-oxazolo[2,3-a]isochinolin durch Salze von Hydroxylamin-Derivaten

Twofold Ring Cleavage of 2,3,5,6-Tetrahydro-10bH-oxazolo[2,3-a]isoquinoline with Salts of Hydroxylamine Derivatives Contrary to literature the reaction of the cyclic carbinolamine ether 1 with hydroxylamine hydrochloride don't give the N-hydroxyaminal hydrochloride 2 · HCl, but the ring opened E-oxime amine hydrochloride 3 · HCl. The structure is proved with NMR- and UV-spectroscopic methods. Similar products 11 · HCl - 15 · HCl and 18 · HCl/ 19 · HCl are available from salts of hydroxylamine ethers and semicarbazides. The reactivity of 1 and the stability of the products are investigated.     

Synthese von substituierten γ-Ketosäuren durch alkalische Ringöffnung von 1,1-disubstituierten Cyclopentandionen-(2,5)

Synthesis of Substituted γ-keto-acids via Alkaline Ring Opening of 1,1-Disubstituted Cyclopentane-2,5-diones 1,1-Disubstituted cyclopentane-2,5-diones are smoothly and completely converted by aqueous sodium hydroxide into substituted γ-keto-acids. This reaction is remarkable, because 1-monosubstituted cyclopentane-2,5-diones are not cleaved hydrolytically even under more drastical reaction conditions.     

Unterscheidung von Palmölen und Palmöl-Fraktionen durch HPLC der Triglyceride

Analytical Characterisation of Palm Oil Fractions by HPLC of Triglycerides The increasing importance of palm oils and palm oil fractions in international trade makes it necessary to develop analytical criteria for the characterisation of these products. One problem is the correct identification of palm oleins, which are often difficult to distinguish from palm oils. These products frequently exhibit similar fatty acid by GLC and similar iodine values. The correct identification of palm stearins by GLC is comparatively more easy. Palm oleins and palm oils can be characterized by HPLC using conditions that permit not only the separation of triolein from less unsaturated triglycerides of the same carbon number, but also, at the same time, a separation of tripalmitin from triglycerides containing oleic acid. By establishing the peak area ratios for a number of selected triglycerides a clear differentiation between palm oils and palm oleins, as well as various other palm oil fractions and their mixtures is obtained.     

Abtrennung und Rückgewinnung von gasförmigen Stoffen durch Adsorption

Separation and recovery of gaseous substances by adsorption. After making a number of fundamental remarks on adsorbents, equilibrium, and kinetics of adsorption from the gas phase, the authors of this article first present a variety of regeneration methods. There follows a brief account of the methods used in the design of fixed bed adsorbers. The reader is then led via considerations of safety in the construction and operation of adsorbers to a number of practical examples from the areas of solvent recovery and flue gas purification.     

Gewinnung von Öl durch Schwelen von Ölschiefer und Teersand als Beitrag zur Energieversorgung

The contribution to energy supply of oil recovered by distillation of oil shale and tar sands . Following a world-wide survey of the most important deposits of oil shale and tar sands, the current activities in the USSR, China and Canada in the field of the industrial recovery of shale oil and bitumen from tar sand are described in broad terms. Thereafter, the current large-scale projects for the production of synthesis oil from these feedstocks are dealt with. The operating method and development status of modern processes for distilling oil shale are covered, as is the working principle of the hot water extraction of tar sand which is already commercially in application. The LR-Process method of operation and its especial feature of circulating the distilled residue as solid heat carrier are discussed in more detail. This is followed by information on the throughput potential of this process. The characteristic reactions influencing the quality of the LR products (oil, gas, residue, flue gas) are handled. Typical quality data for oil and gas obtained from oil shale and tar sands are given. A route is indicated for further processing of the condensate streams from the Lurgi-Ruhrgas Process. This consists of precipitation of solids, distillative separations and one hydrogenation step for the naphtha and oil fraction. These process steps produce a ?syncrude”? which can be further processed together with crude oil in conventional refineries. Examples are given for the independent further processing of syncrude to end-products customary on the market.     

Separation von Feststoffen aus Fetten und Ölen durch Elektrophorese

Separation of Solids from Fats and Oils by Electrophoresis The development of PETRECOR ELECTROFILTER^TM SEPARATOR provides the food industry with plants that enable the separation of solid particles, including those in the submicron region (< 0.5 μm), from fats and oils with the aid of high-voltage electrical field. The most important commercial application is the removal of bleaching earth and nickel catalyst; a final polishing filtration becomes unnecessary. Results of pilot plant operation show, for example in the removal of nickel catalyst from hydrogenated soybean oil, a continuous reduction of nickel from 500 ppm to < 0.15 ppm. These plants are completely closed systems under slight pressure with a definite precalculated capacity for solids; the latter can be removed by a simple regeneration process involving rinsing with the product to be treated. This regenerating liquid is a pumpable suspension containing ca. 5% solids; it is subjected to further treatment. Plants of various sizes with respect to maximum flow rate and capacity are available. The layout is always done for the specific application.     

Aufklärung der Molekülstruktur von Rohölinhaltsstoffen durch NMR-Spektroskopie. IV. Strukturtypen- und Strukturgruppenanalyse von Erdölfraktionen durch 1H-NMR-Spektroskopie

Elucidation of the Molecular Structure of Petroleum Constituents by N.M.R. Spectroscopy. IV. Analysis of Petroleum Fractions with Respect to Types of Structure and Structural Groups by ¹H N.M.R. Spectroscopy An improved method is presented which permits a quantitative analysis of crude oil products with a final boiling point below 400°C by means of the data of the ¹H n.m.r. spectrum and the average boiling point of the petroleum fractions. The types of aromatic structures are distinguished with respect to mono-, bi-, and tricyclic aromatics, and additionally, further structural group information is obtained.     

Verbesserte Prognose durch Behandlung von Fettstoffwechselstörungen-Ergebnisse und Schlüsse aus Interventionsstudien

Improved Prognosis by Treatment of Lipoprotein Disorders-Results and Conclusions from Intervention Trials The relationship between lowering of (LDL)cholesterol and coronary heart disease has been proved in a number of primary and secondary intervention trials. The frequency of coronary events could be lowered by 25-34% applying drugs (clofibrate, cholestyramine, gemfibrozil) in primary intervention trials. The positive effect of adequate lipid lowering means has been shown in intervention trials (mainly controlled by angiography) inspite of the different means of intervention (diet, drugs, ileal bypass surgery, LDL-apheresis). The best effect could be reached by lowering LDL-cholesterol to values around 120 mg/dl. Differences in total mortality in these trials could not be expected because of age and number of the participants. There were no hints for an increased number of suizides due to lowering of cholesterol.