Various Ozonides of Rubber and the General Question of the Existence of Primary Ozonides

1937 ◽  
Vol 10 (1) ◽  
pp. 114-119
Author(s):  
R. Pummerer
Keyword(s):  
Organic Chemistry ◽  
Experimental Data ◽  
Double Bond ◽  
Carbon Chain ◽  
Mesityl Oxide ◽  
General Question ◽  
Addition Reactions ◽  
Reaction Products ◽  
Important Method ◽  
General Acceptance

Abstract Harries was the first to make use of ozone cleavage at the carbon double bond of unsaturated compounds as an important method of research in organic chemistry. However, the formula (see PDF for diagram) of Harries, which is founded on its analogy with the products of other addition reactions, rests on scanty experimental data. One of the chief arguments against the formula is the absence of glycols as reaction products by the action of the most varied types of reducing agents. This latter fact, in conjunction with certain polymerization phenomena, led Staudinger to propose an isoozonide type of formula, in which the carbon chain has been opened, thus (see PDF for diagram) According to Staudinger, these isoozonides are formed very readily by transposition from primary or molozonides, and they are stable compounds. On the contrary, some molozonides are stabilized by polymerization. The constitution of butylene ozonide was proved synthetically by Rieche and Meister to be that of an isoozonide, and today the isoozonide formula has received general acceptance. In spite of these facts, some of the results of Harries, on which he based his original ozonide formula, remain unchallenged; for instance, the fact that when heated the ozonide of mesityl oxide reverts to mesityl oxide, and the fact that fumaric acid forms with ozone a loose compound from which ozone is liberated easily. In view of this, it appeared as if the Harries formula would really turn out to be the correct one, and that stable molozonides should exist.

Rubber. XVIII. Various Ozonides of Rubber and the Problem of the Existence of the Primary Ozonides of Harries

1938 ◽  
Vol 11 (1) ◽  
pp. 7-31
Author(s):  
Rudolf Pummerer ◽  
Hermann Richtzenhain
Keyword(s):  
Carbon Chain ◽  
Mesityl Oxide ◽  
Addition Reactions ◽  
Reaction Products ◽  
Primary Reaction ◽  
Carbon Chains ◽  
Fundamental Objection ◽  
Great Stress ◽  
Valuable Service ◽  
General Method

Abstract A permanently valuable service was rendered by Harries when he introduced the ozone cleavage of unsaturated compounds as a general method of investigation in organic chemistry. By analogy with other addition reactions of double bonded carbon atoms he derived the formula (a) for the ozonides which are first formed, but to support the existence of which he was able to obtain only scant experimental data. Harries relied above all on two observations, first, that mesityl oxide ozonide reverts to mesityl oxide when heated by itself, and, secondly, that fumaric acid is supposed to combine loosely with ozone and then readily split off again. Both of these suppositions have remained undisputed up to the present time. Harries reported that it was not possible, with any of a wide variety of reducing agents, to reduce the ozonides to the original compounds or to 1,2-glycols, as would be expected from their structure. Staudinger has laid great stress on this fundamental objection, and he considers that most ozonides have an isoözinide formula, as shown by formula (b) above, in which the carbon chain is already ruptured, so that by reduction only the usual types of cleavage products rather than glycols with intact carbon chains can be formed, as has been found experimentally. Staudinger assumed that the primary reaction products of treatment with ozone are molozonides containing the group:

TRIGLYCERIDE COMPOSITION OF SIXTEEN STRAINS OF MARINE DIATOM

2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Lily M.G. Panggabean ◽  
Abdullah Rasyid ◽  
Zarrah Duniani ◽  
Yana Meliana ◽  
Indah Kurniasih
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acid ◽  
Double Bond ◽  
Unsaturated Fatty Acid ◽  
Ion Trap ◽  
Carbon Chain ◽  
Highly Unsaturated Fatty Acid ◽  
Marine Diatom ◽  
Ion Trap Mass Spectrometry ◽  
Spectra Analysis

Trigliceride or triacylglicerol (TAG) composition in crude oil of sixteen strain of marine diatom has been detected by spectra analyses on an Electrospray - Ion Trap – Mass Spectrometry (ESI-IT-MS) HCT Bruker-Daltonic GmbH instrument with AgNO3 used as coordination ionization agent. Biomass samples of each microalga strain were taken from early and late stationary cultures in f/2 enriched seawater and algal oils were extracted according to Bligh and Dyer. Results from spectra analysis showed that P-Pt-P (C16:0-C16:1-C16:0) were distinguished in TAG from diatom strains Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.1, Thalasiossira sp.2, Thalasiossira sp.3, Navicula sp. 1, Navicula sp. 2, Navicula sp. 3, Navicula sp. 4, Nitzschia sp. 2 and Amphora sp. In contrast, TAGs in Melosira sp. included P-P-P (C16:0-C16:0-C16:0) and P-P-O (C16:0-C16:0-C18:1) were identified. TAGs from Chaetoceros sp. were the most varies among samples, i.e. P-Pt-P (C16:0-C16:1-C16:0), A-P-M (C20:4-C16:0-C14:0), P-Pt-Lt (C16:0-C16:1-C18:3), P-Pt-A (C16:0-C16:1-C20:4), D-P-P (C22:6-C16:0-C16:0), A-Ln-P (C20:4-C18:2-C16:0). Various TAGs were also detected in Nitzschia sp.2, i.e. P-Pt-M (C16:0-C16:1-C14:0), P-Pt-P (C16:0-C16:1-C16:0), P-Pt-S (C16:0-C16:1-C18:0), P-Pt-A (C16:0-C16:1-C20:4). TAGs composition in Skeletonema strains that similar to those in Nitzschia sp.1 has longer carbon, i.e. P-P-O (C16:0-C16:0-C18:1), P-O-O (C16:0-C18:1-C18:1) and O-O-O (C18:1-C18:1-C18:1). TAGs with longer carbon chain and more double bond including highly unsaturated fatty acid C20:4 were increased with culture age in diatoms Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.2, Navicula sp.1 and Nitzschia sp. 2.Keywords: diatom, TAG, ESI-IT-MS, f/2, early and late stationary

scholarly journals Impact of Chitosan-Genipin Films on Volatile Profile of Wine along Storage

2021 ◽  
Vol 11 (14) ◽  
pp. 6294
Author(s):  
M. Angélica Rocha ◽  
Manuel Coimbra ◽  
Sílvia Rocha ◽  
Cláudia Nunes
Keyword(s):  
Volatile Compounds ◽  
Carbon Chain ◽  
White Wine ◽  
Maillard Reaction Products ◽  
Red Wines ◽  
Reaction Products ◽  
Ethyl Hexanoate ◽  
Organoleptic Characteristics ◽  
Strecker Aldehydes ◽  
Key Odorants

Chitosan-genipin films have been proposed for preservation of white wine, maintaining their varietal key odorants and organoleptic characteristics of sulfur dioxide treated wines. Nevertheless, these wines showed aroma notes that slightly distinguish them. It is possible that during the contact of films with wine for at least 2 months, after fermentation and prior to bottling, interactions or chemical reactions are promoted. In this work, wine model solutions with volatile compounds in contact with chitosan-genipin films were performed to evaluate their evolution along time. To complement these analyses, the volatile compounds of white and red wines kept in contact with chitosan-genipin films during 2 and 8 months were also studied. The results obtained allowed us to conclude that the contact of chitosan-genipin films with both white and red wines tend to retain long carbon chain volatile compounds, such as ethyl hexanoate and octan-3-one. It also promoted the formation of Maillard reaction products, such as furfural by dehydration of pentoses and Strecker aldehydes, such as 3-methylbutanal and phenylacetaldehyde, by degradation of amino acids. This study reveals that the use of chitosan-genipin films for wine preservation is also able to promote the formation of compounds that can modulate the wines aroma, maintaining the varietal notes.

scholarly journals Kinetics study on non-isothermal thermochemical liquefaction of corncobs in ethanol-water solution: Effect of ethanol concentration

2018 ◽  
Vol 197 ◽  
pp. 09005
Author(s):  
Bregas Siswahjono Tatag Sembodo ◽  
Hary Sulistyo ◽  
Wahyudi Budi Sediawan ◽  
Mohammad Fahrurrozi
Keyword(s):  
Experimental Data ◽  
Kinetic Models ◽  
Ethanol Concentration ◽  
Water Solution ◽  
Reaction Products ◽  
Gaseous Products ◽  
Bio Oil ◽  
Volatile Products ◽  
Calculation Results ◽  
Oil Gas

Corncobs are potentially processed into bio-oil through thermochemical liquefaction processes. It is difficult to construct kinetics models based on the compounds involved in the reaction. It would be made four kinetic models based on four reaction products, i.e., solids, bio-oil, gas and volatile products. The purposes of the study were to seek kinetics model of thermochemical liquefaction of corncobs in ethanol-water solution and to study the effect of ethanol concentration. The experiment of liquefaction processes of corncobs in ethanol-water solution using sodium carbonate catalyst was performed in the 150 ml autoclave equipped with a magnetic stirrer in the temperature up to 280°C. Four kinetic models were applied to predict the yield of four reaction product lumps. The calculation results were compared to the experimental data. Compared to the others, model 4 was the most realistic and closely matching to the experimental data. In model 4 the reaction mechanism was assumed that biomass (corncobs) first decomposed into bio-oil, followed by decomposition of bio-oil into volatile products reversibly and, finally, volatile products decomposed into gaseous products. The yield of bio-oil increased from 42.05% to 54.93% by increasing to ethanol concentration of 0% to 40%.

scholarly journals Heterogeneous acidic catalysts for the tetrahydropyranylation of alcohols and phenols in green ethereal solvents

2018 ◽  
Vol 14 ◽  
pp. 1655-1659 ◽  
Author(s):  
Ugo Azzena ◽  
Massimo Carraro ◽  
Gloria Modugno ◽  
Luisa Pisano ◽  
Luigi Urtis
Keyword(s):  
Organic Chemistry ◽  
Heterogeneous Catalysis ◽  
Important Class ◽  
Green Solvents ◽  
Reaction Products ◽  
Reaction Conditions ◽  
One Pot ◽  
Acidic Catalysts ◽  
Set Up ◽  
Work Up

The application of heterogeneous catalysis and green solvents to the set up of widely employed reactions is a challenge in contemporary organic chemistry. We applied such an approach to the synthesis and further conversion of tetrahydropyranyl ethers, an important class of compounds widely employed in multistep syntheses. Several alcohols and phenols were almost quantitatively converted into the corresponding tetrahydropyranyl ethers in cyclopentyl methyl ether or 2-methyltetrahydrofuran employing NH4HSO4 supported on SiO2 as a recyclable acidic catalyst. Easy work up of the reaction mixtures and the versatility of the solvents allowed further conversion of the reaction products under one-pot reaction conditions.

Catalytic Isomerization of Olefins and Theirs Derivatives: A Brief Overview

2021 ◽  
Author(s):  
Wangjing Ma ◽  
Bonan Liu ◽  
Duanda Wang ◽  
Jun Zhao ◽  
Lu Zhang ◽  
...  
Keyword(s):  
Natural Products ◽  
Double Bond ◽  
Recent Work ◽  
Organic Compounds ◽  
Organic Synthesis ◽  
Carbon Chain ◽  
Vital Role ◽  
Carbon Double Bond ◽  
Catalytic Isomerization ◽  
The 1960S

Carbon–carbon double bond (CCDB) isomerization is a method for synthesizing new organic compounds from olefins and their derivatives, which was based on C=C migration along carbon chain and cis/trans transform, and it plays a vital role in the fields of organic synthesis, synthesis of daily chemicals, raw oil’s development and synthesis of natural products and so on. In this paper, advances of five types of catalytic methods for CCDB of olefins and their derivatives since the 1960s were discussed in detail; Based on his recent work, the author mainly introduces the application and development of photocatalysis in CCDB of olefins and their derivatives.

scholarly journals Photochemical aging of atmospherically reactive organic compounds involving brown carbon at the air-aqueous interface

2019 ◽  
Author(s):  
Siyang Li ◽  
Xiaotong Jiang ◽  
Marie Roveretto ◽  
Christian George ◽  
Ling Liu ◽  
...  
Keyword(s):  
Double Bond ◽  
Organic Compounds ◽  
Uv Light ◽  
Carbon Chain ◽  
Organic Coating ◽  
Organic Films ◽  
Carbon Chain Length ◽  
Aerosol Composition ◽  
Brown Carbon ◽  
Photochemical Aging

Abstract. Photosensitizing compounds containing brown carbon can absorb UV light and transfer that energy to low volatile organic compounds at the surface of aqueous particles. To better understand the reactivity and photochemical aging processes of organic coating on the aqueous aerosol surface, we have simulated the photosensitized reaction of organic films made of several long chain fatty acids in a Langmuir trough in the presence or absence of irradiation. Several chemicals (imidazole-2-carboxaldehyde and humic acid), PM2.5 samples collected from the field and secondary organic aerosols samples generated from a simulation chamber were used as photosensitizers to be involved in the photochemistry of the organic films. Stearic acid, elaidic acid, oleic acid and two different phospholipids with the same carbon chain length and different degrees of saturation i.e., 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and 1,2-dioleoylsn-glycero-3-phosphocholine (DOPC) were chosen as the common organic film-forming species in this analysis. The double bond (trans and cis) in unsaturated organic compounds has an effect on the surface area of the organic monolayer. The OA monolayer possessing a cis double bond in an alkyl chain is more expanded than EA monolayers on artificial seawater that contain a photosensitizer. Monitoring the change in the relative area of DOPC monolayers has shown that DOPC does not react with photosensitizers under dark conditions. Instead, the photochemical reaction initiated by the excited photosensitizer and molecular oxygen can generate hydroperoxidation in the DOPC monolayers, accompanied by an increase in the molecular area. The DSPC monolayers did not yield any photochemical oxidized products under the same conditions. The spectra measured with polarization modulation-infrared reflection absorption spectroscopy (PM-IRRAS) were also consistent with the results of a surface pressure-area isotherm. Here, a reaction mechanism explaining these observations is presented and discussed. The results will contribute to our understanding of the processing of organic aerosol aging that controls the aerosol composition.

scholarly journals Study of Refractive Indices and Its Theories for Mixtures of N, N-Diethylethanamine and Acetates

2020 ◽  
Vol 12 (3) ◽  
pp. 363-370
Author(s):  
P. Tyagi ◽  
K. Kumar ◽  
M. Rani ◽  
N. Sabharwal
Keyword(s):  
Experimental Data ◽  
Methyl Acetate ◽  
Butyl Acetate ◽  
Composition Range ◽  
Polynomial Equation ◽  
Carbon Chain ◽  
Refractive Indices ◽  
Carbon Chain Length ◽  
Propyl Acetate ◽  
Empirical Correlations

This paper reports the refractive indices ( ) of N,N-diethylethanamine + methyl acetate, ethyl acetate, propyl acetate, butyl acetate and pentyl acetate at 298.15 K and at different composition range. The various empirical correlations like Arago-Biot (AB), Gladstone-Dale (GD), Lorentz-Lorenz (L-L) Heller (H), Weiner (W), Newton (Nw) and Erying-John (E-J) were applied to experimental data for estimating theoretical value of refractive indices. For an equimolar mixture, the predicted deviation in refractive index values is consistent well with the experimental data. It has been found that the interactions between amine and different esters decrease when carbon chain length in ester increases. Also refractive indices are affected with change in temperature. To evaluate the standard deviation, RK polynomial equation was fitted to the measured refractive indices data.

Aprotic Conjugate Addition Reactions of Lithiated Allylic Sulfoxides With Acyclic Enones; a Breakdown of the trans-Decalyl Transition State

1989 ◽  
Vol 42 (10) ◽  
pp. 1785 ◽  
Author(s):  
RK Haynes ◽  
AG Katsifis ◽  
LM King ◽  
SC Vonwiller
Keyword(s):  
Transition State ◽  
Conjugate Addition ◽  
Vinyl Ketone ◽  
Methyl Vinyl Ketone ◽  
Mesityl Oxide ◽  
Addition Reactions ◽  
State Characteristic ◽  
Methyl Vinyl ◽  
Cyclic Enones ◽  
Carbonyl Addition

The reactions of lithiated 1-(t-butylsulfinyl)prop-2-ene, 1-(t-butylsulfinyl)-3-methylbut-2-ene, 1-(t-butylsulfinyl)but-2-ene, 1-(phenylsulfinyl)but-2-ene and 2-methyl-1-(phenylsu1finyl)prop- 2-ene with methyl vinyl ketone, mesityl oxide and crotonaldehyde give largely carbonyl addition products arising from reaction through C1 or C3 of the allyl system. In the case of methyl crotonate, conjugate addition through C3 is observed. The initially formed diastereomers of the C1 adducts, allylic sulfoxides, are configurationally unstable. Only the lithiated 1-(t-butylsulfinyl)-3-methylbut-2-ene undergoes conjugate addition with methyl vinyl ketone to give an (E)-vinyl sulfoxide whose formation may involve the trans-decalyl transition state characteristic of the reactions of lithiated allylic sulfoxides with cyclic enones.

Sign in / Sign up

Export Citation Format

Share Document