Saturated Alcohols Research Articles

Rapid Untargeted Puff‐by‐Puff Analysis of (Electronic) Cigarette Emissions by Concentric Dielectric Barrier Discharge Ionisation Mass Spectrometry

Despite the soaring popularity of e‐cigarettes among teenagers and young adults, our understanding of the full extent of their health hazards have remained limited. This is due to the vast complexities of e‐cigarette aerosols and the difficulty in their full characterisation. Conventional mass spectrometry methods of e‐cigarette analysis, though pioneering in driving political and medical discourse, have been limited in their capabilities to uncover all compounds in its emissions due to prominent limitations in experimental setup. To overcome this major hurdle, we have developed a setup for puff‐by‐puff analysis of electronic and conventional cigarette emissions by concentric dielectric barrier discharge ionisation mass spectrometry. In this pilot study, the simple setup of in‐line dilution and high‐resolution mass spectrometry analysis allowed us to directly uncover 225 compounds in e‐cigarette puffs across a wide spectrum of chemical characteristics in two sequential 5‐minute runs. These include acids, carbonyls, aromatic cyclics, heterocyclics, unsaturated and saturated hydrocarbons, alcohols, esters, alkaloids, sulfur‐containing compounds, oxides, and nitriles. As a result, our setup provided a significant improvement in rapid compound identification, and demonstrated a much broader chemical landscape in e‐cigarette emissions than previously reported.

Direct Synthesis of Saturated Alcohols from Conjugated Ketones Using NaBH4 and Catalytic Amount of CuCN in Ethanol: Additive Catalysis with a Lithium Salt or a Sodium Salt.

A direct, efficient, and highly chemoselective synthesis of saturated alcohols through one-pot sequential 1,4- and 1,2-reduction of cyclic and acyclic conjugated ketones is reported. The saturated alcohols are obtained in very good yields using sodium borohydride (NaBH4) as a reducing agent and a catalytic amount of copper(I) cyanide (CuCN) in ethanol as a green solvent. This nontoxic solvent significantly favors full 1,4-reduction, as opposed to methanol. Selectivity is further enhanced by the combination of two additives (a lithium salt or a sodium salt, such as NaI).

Stereocontrolled Hydrogenation of Conjugated Enones to Alcohols via Dual Iridium-Catalysis.

The concept of dual catalysis is an emerging area holding high potential in terms of preparative efficiency, yet faces severe challenges in compatibility of reaction conditions and interference of catalysts. The transition-metal catalyzed stereoselective hydrogenation of olefins and ketones typically proceeds under different reaction conditions and/or uses a different reductant. As a result, these two types of hydrogenations can normally not be performed in the same pot. Herein, the stereocontrolled hydrogenation of enones to saturated alcohols is described, enabled by orthogonal dual iridium catalysis, using molecular hydrogen for both reductions. In this one-pot procedure, N,P-iridium catalysts (hydrogenation active towards olefins) and NHC,P-iridium catalysts (hydrogenation active towards ketones) operated independently of one another allowing the construction of two contiguous stereogenic centers up to 99% ee, 99/1 d.r. Ultimately, by simple selection of the chirality of either ligands, the enone could be efficiently reducedto allfour stereoisomers of the saturated alcohol in equally high stereopurity. This degree of stereocontrol for the synthesis of different stereoisomers by dual transition-metal catalyzed hydrogenation was previously not attained. The generality in substituted enones (alkyl, aryl, heteroaryl) demonstrate the wide applicability of this concept.

Stereocontrolled Hydrogenation of Conjugated Enones to Alcohols via Dual Iridium‐Catalysis

The concept of dual catalysis is an emerging area holding high potential in terms of preparative efficiency, yet faces severe challenges in compatibility of reaction conditions and interference of catalysts. The transition‐metal catalyzed stereoselective hydrogenation of olefins and ketones typically proceeds under different reaction conditions and/or uses a different reductant. As a result, these two types of hydrogenations can normally not be performed in the same pot. Herein, the stereocontrolled hydrogenation of enones to saturated alcohols is described, enabled by orthogonal dual iridium catalysis, using molecular hydrogen for both reductions. In this one‐pot procedure, N,P‐iridium catalysts (hydrogenation active towards olefins) and NHC,P‐iridium catalysts (hydrogenation active towards ketones) operated independently of one another allowing the construction of two contiguous stereogenic centers up to 99% ee, 99/1 d.r. Ultimately, by simple selection of the chirality of either ligands, the enone could be efficiently reduced to all four stereoisomers of the saturated alcohol in equally high stereopurity. This degree of stereocontrol for the synthesis of different stereoisomers by dual transition‐metal catalyzed hydrogenation was previously not attained. The generality in substituted enones (alkyl, aryl, heteroaryl) demonstrate the wide applicability of this concept.

Design and Understanding of Adaptive Hydrogenation Catalysts Triggered by the H2/CO2-Formic Acid Equilibrium.

An adaptive catalytic system for selective hydrogenation was developed exploiting the H2+CO2HCOOH equilibrium for reversible, rapid, and robust on/off switch of the ketone hydrogenation activity of ruthenium nanoparticles (Ru NPs). The catalyst design was based on mechanistic studies and DFT calculations demonstrating that adsorption of formic acid to Ru NPs on silica results in surface formate species that prevent C═O hydrogenation. Ru NPs were immobilized on readily accessible silica supports modified with guanidinium-based ionic liquid phases (Ru@SILPGB) to generate in situ sufficient amounts of HCOOH when CO2 was introduced into the H2 feed gas for switching off ketone hydrogenation while maintaining the activity for hydrogenation of olefinic and aromatic C═C bonds. Upon shutting down the CO2 supply, the C═O hydrogenation activity was restored in real time due to the rapid decarboxylation of the surface formate species without the need for any changes in the reaction conditions. Thus, the newly developed Ru@SILPGB catalysts allow controlled and alternating production of either saturated alcohols or ketones from unsaturated substrates depending on the use of H2 or H2/CO2 as feed gas. The major prerequisite for design of adaptive catalytic systems based on CO2 as trigger is the ability to shift the H2+CO2HCOOH equilibrium sufficiently to exploit competing adsorption of surface formate and targeted functional groups. Thus, the concept can be expected to be more generally applicable beyond ruthenium as the active metal, paving the way for next-generation adaptive catalytic systems in hydrogenation reactions more broadly.

A GC-MS Metabolic Study on Lipophilic Compounds in the Leaves of Common Wheat Triticum aestivum L.

Common wheat (Triticum aestivum L.) is one of the most valuable cereal crops worldwide. This study examined leaf extracts of 30 accessions of T. aestivum and its subspecies using 48 h maceration with methanol by GC-MS and GCxGC-MS. The plants were grown from seeds of the wheat genetics collection of the Wheat Genetics Sector of the Institute of Cytology and Genetics, SB RAS. The analysis revealed 263 components of epicuticular waxes, including linear and branched alkanes, aliphatic alcohols, aldehydes, ketones, β-diketones, carboxylic acids and their derivatives, mono- and diterpenes, phytosterols, and tocopherols. Hierarchical cluster analysis and principal component analysis were used to identify and visualize the differences between the leaf extracts of different wheat cultivars. Three clusters were identified, with the leading components being (1) octacosan-1-ol, (2) esters of saturated and unsaturated alcohols, and (3) fatty acid alkylamides, which were found for the first time in plant extracts. The results highlight the importance of metabolic studies in understanding the adaptive mechanisms and increasing wheat resistance to stress factors. These are crucial for breeding new-generation cultivars with improved traits.

Non-Target Screening of Chemicals in Selected Cotton Products by GC/MS and Their Safety Assessment.

Cotton is used for the production of textiles, hygiene and cosmetic materials. During cultivation and technological processes, various types of substances (surfactants, softeners, lubricants, etc.) penetrate cotton, which can have a harmful effect on both the human body and the environment. The aim of this study was to analyze selected cotton products in order to identify the substances contained and to describe the potential possibilities of inducing textile contact dermatitis (CD). The impact of the identified compounds on the aquatic environment was also taken into account. Nine samples of cotton clothing and seven samples of cotton pads from various manufacturers were tested. Samples after extraction using the FUSLE (Focused Ultrasonic Liquid Extraction) technique were analyzed with GC/MS. Qualitative analysis was based on comparing mass spectra with library spectra using the following mass spectra deconvolution programs: MassHunter (Agilent), AMDIS (NIST), and PARADISE (University of Copenhagen). The parameter confirming the identification of the substance was the retention index. Through the non-target screening process, a total of 36 substances were identified, with an average AMDIS match factor of approximately 900 ("excellent match"). Analyzing the properties of the identified compounds, it can be concluded that most of them have potential properties that can cause CD, also due to the relatively high content in samples. This applies primarily to long-chain alkanes (C25-C31), saturated fatty acids, fatty alcohols (e.g., oleyl alcohol), and fatty acid amides (e.g., oleamide). However, there are not many reports describing cases of cotton CD. Information on the identified groups of compounds may be helpful in the case of unexplained sources of sensitization when the skin comes into contact with cotton materials. Some of the identified compounds are also classified as dangerous for aquatic organisms, especially if they can be released during laundering.

Eryngial: An α,β-Unsaturated Fatty Aldehyde as the Major Phytotoxin in Spiny Coriander (Eryngium foetidum L.) Essential Oil.

Weed species many times possess allelochemicals as a part of their survival strategy. These metabolites can be potential targets in search of natural phytotoxins. This study aims to evaluate the phytotoxic ability of fatty aldehyde-rich essential oil from spiny coriander (Eryngium foetidum) leaves, also known as fitweed or spiritweed and to further identify the active phytotoxins. This oil dose-dependently inhibited the wheatgrass coleoptile and radicle growth in multiple bioassays with half maximal inhibitory concentration (IC50) 30.6-56.7 μg/mL, while exhibiting a less pronounced effect on the germination (IC50 181.8 μg/mL). The phytotoxicity assessment of two oil constituents identified eryngial (trans-2-dodecenal), exclusively major fatty aldehydic constituent as the potent growth inhibitor with IC50 in the range 20.8-36.2 μg/mL during an early phase of wheatgrass emergence. Eryngial-inspired screening of eleven saturated fatty aldehydes and alcohols did not find a significantly higher phytotoxic potency. In an open vessel, eryngial as the supplementation in agar medium, dose-dependently inhibited the growth of pre-germinated seeds of one monocot (bermudagrass) and one dicot (green amaranth) weed species with IC50 in the range 23.8-65.4 μg/mL. The current study identified eryngial, an α,β-unsaturated fatty aldehyde of coriander origin to be a promising phytotoxic candidate for weed control.

First Steps towards Pre-Breeding of Sideritis scardica: A Phenotypic, Agronomic, and Phytochemical Profiling Approach

Sideritis scardica (S. scardica) Griseb., also known as mountain tea, is an important medicinal and aromatic plant species. Due to the high cross-pollination ability of the species, diverse genotypes and phenotypes occur naturally. Considering that superior uniform genotypes are necessary for highly qualitative and sustainable production, this study aimed to conduct a pre-breeding evaluation of three clones (SID1, SID2, and SID3) originating from a selected S. scardica population growing in Greece. According to a phenotypic and agronomic evaluation, SID2 seemed to be superior among the three clones, expressing a good profile with desirable traits (i.e., desired inflorescence length and leaf surface, high length of stems, and high fresh and dry plant biomass). Furthermore, SID3 presented some remarkable measurements regarding morphological (upright growth habit) and agronomic (high number of stems and plant dry weight, desired plant surface) traits. The phytochemical profile of the three clones was assessed with regard to their volatile and polyphenolic compounds. Forty-four constituents were identified in S. scardica essential oil, including hydrocarbon monoterpenes, sesquiterpenoids, oxygenated monoterpenes, and other groups (monoterpene ketones, saturated fatty alcohols, benzoic esters). Liquid chromatographic analysis revealed SID2 as the clone most abundant in the major polyphenolic metabolites: verbascoside (2234.3 mg 100 g−1), isoscutellarein-7-O [6″-O-acetyl]-allosyl(1 → 2) glucoside (1456.5 mg 100 g−1), and 4-methyl hypolaetin-7-O [6″-O-acetyl]-allosyl(1 → 2) glucoside (861.8 mg 100 g−1). The results indicate the ability to combine morphological, agronomic, and phytochemical traits, in order to identify superior S. scardica genotypes for further evaluation and utilization in breeding programs, aiming to create cultivars or varieties for farming purposes with desired performance and high quantitative and qualitative yields.

Production of high-carbon-number naphthenes for bio-aviation fuels from bio-crude prepared by fast pyrolysis of lignocellulose

Lignocellulose has been suggested as a cost-effective, environmentally sustainable substitute for paraffins, aromatics, and naphthenes in aviation fuel. However, bio-crude derived from the fast pyrolysis of lignocellulose poses challenges because of its high acidity and viscosity arising from oxygenates and water; in addition, the low-carbon-number hydrocarbons obtained from lignocellulose-derived sugars and phenols are unsuitable for aviation fuels. In this investigation, high-carbon-number hydrocarbon fuels are generated from bio-crude through condensation reactions between phenols and saturated cyclic alcohols, achieving a heavy fraction similar to that of aviation fuels. The one-pass, four-step continuous-flow reaction of bio-crude is conducted using a catalysis reactor equipped with carbon-supported palladium, titania-supported nickel–iron, hydrogen-form zeolite Y, and tungstate–zirconia-supported ruthenium. In contrast with conventional two-step hydrodeoxygenation methods yielding 1.1% dimeric cycloalkanes, the suggested multi-step reaction produced 4.5 to 4.7% yields of heavier naphthenes containing twelve or more carbon atoms.

Gas-Phase Kinetic Investigation of the OH-Initiated Oxidation of a Series of Methyl-Butenols under Simulated Atmospheric Conditions.

Five biogenic unsaturated alcohols have been investigated under simulated atmospheric conditions regarding their gas-phase OH reactivity. The gas-phase rate coefficients of OH radicals with 2-methyl-3-buten-2-ol (k1), 3-methyl-2-buten-1-ol (k2), 3-methyl-3-buten-1-ol (k3), 2-methyl-3-buten-1-ol (k4), and 3-methyl-3-buten-2-ol (k5) at 298 ± 2 K and 1000 ± 10 mbar total pressure of synthetic air were determined under low- and high-NOx conditions using the relative kinetic technique. The present work provides for the first time the rate coefficients of gas-phase reactions of hydroxyl radicals with 2-methyl-3-buten-1-ol and 3-methyl-3-buten-2-ol. The following rate constants were measured (in 10-11 cm3 molecule-1 s-1): k1 = 6.32 ± 0.49, k2 = 14.55 ± 0.93, k3 = 10.04 ± 0.78, k4 = 5.31 ± 0.37, and k5 = 11.71 ± 1.29. No significant differences in the measured rate coefficients were obtained when either 365 nm photolysis of CH3ONO in the presence of NO or 254 nm photolysis of H2O2 was used as a source of OH radicals. Reactivity toward other classes of related compounds such as alkenes and saturated alcohols is discussed. A comparison of the structure-activity relationship (SAR) estimates derived from the available accepted methodologies with experimental data available for unsaturated alcohols is provided. Atmospheric lifetimes for the investigated series of alkenols with respect to the main atmospheric oxidants are given and discussed.

The effect of instant tea on the aroma of duck meat

Tea products, such as instant tea, have been shown to improve the aroma of meat products. However, the mechanisms by which tea products enhance meat aroma have not been adequately explained. In this study, we analyzed the impact of instant tea on the aroma of duck meat. Our results showed that treatment with instant tea led to increases in floral, baked, and grassy notes while reducing fishy and fatty notes. Several alcohols, aldehydes, ketones, indole and dihydroactinidiolide exhibited significantly increased OAVs. Conversely, certain saturated aldehydes, unsaturated aldehydes and alcohols displayed significantly decreased OAVs. The enhanced floral, baked and grassy notes were attributed to volatile compounds present in instant tea. The reduction in fishy and fatty notes was linked to polyphenols in instant tea interacting with nonanal, undecanal, (E)-2-octenal, (E)-2-nonenal, (E)-2-decenal, and 2,4-decadienal through hydrophobic interactions and electronic effects. This study enhances our understanding of how tea products improve meat aromas.

Phenalenyl-Based Photocatalyst for Bioinspired Oxidative Dehydrogenation of N-Heterocycles and Benzyl Alcohols.

The environmental benefits of molecular oxygen as the oxidizing agent in oxidation reactions that synthesize fine chemicals cannot be overstated. Increased interest in developing robust photocatalysts is stimulated by the fact that the current photocatalytic transformation boom has made previously inaccessible synthetic approaches possible. Motivated by enzymatic catalysis, employing a reusable phenalenyl-based photocatalyst, we have successfully developed oxidative dehydrogenation utilizing molecular oxygen as a greener oxidant. Under photoinduced oxidative dehydrogenation conditions, different types of saturated N-heterocycles and alcohols were successfully dehydrogenated. The versatility of this bioinspired protocol is demonstrated by the fact that a wide variety of N-heteroaromatics, such as quinoline, carbazole, quinoxaline, acridine, and indole derivatives, as well as aldehydes and ketones, were successfully synthesized. Detailed mechanistic studies validate the proposed mechanism. Fluorescence lifetime and CV experiments revealed the crucial role of water on the efficiency of the reaction. The present protocol also provides chemoselectivity and scalability, leading to superior results and allowing for the functionalization of bioactive molecules at a late stage in a sustainable manner.

Volatile organic compounds in the habitat of the escamolera ant (Liometopum apiculatum Mayr) in Zacatecas, Mexico

Volatile organic compounds (VOCs) take part in the biological processes of insects; however, these compounds have not been determined for genus Liometopum. The objective of this study was to identify the variability of the VOCs found in the Liometopum apiculatum habitat during the exploitation season. During the 2017 preseason and season, 35 air samples were collected from the nests of five L. apiculatum colonies established in crassicaule scrub vegetation; additionally, another 35 samples were taken from their foraging sites. Using a gas chromatograph with an electronic nose detector, the VOCs were identified with the Kovats index. In addition, a principal component analysis (PCA) was carried out to evaluate the intensity variability per season. Fourty-eight VOCs were identified in the L. apiculatum habitat. The most significant VOCs included: saturated hydrocarbon (17%), aldehydes (17%), alcohols (15%), and esters (10%). PCA accounted for 79.5% (PC1=53.8 and PC2=25.7) of the intensity variability of the VOCs in the habitat between seasons. The escamol season was characterized by the 3-methyl-3-sulfonyl butan-1-ol, 2-Methylbutanoic acid, and trimethylamine. This profile of the VOCs in the L. apiculatum habitat is a pioneer work and has future implications for the conservation and sustainable exploitation of the escamolera ant.

Characterisation of fatty acyl reductases of sunflower (Helianthus annuus L.) seed

Long and very long chain fatty alcohols are produced from their corresponding acyl-CoAs through the activity of fatty acyl reductases (FARs). Fatty alcohols are important components of the cuticle that protects aerial plant organs, and they are metabolic intermediates in the synthesis of the wax esters in the hull of sunflower (Helianthus annuus) seeds. Genes encoding 4 different FARs (named HaFAR2, HaFAR3, HaFAR4 and HaFAR5) were identified using BLAST, and studies showed that four of the genes were expressed in seed hulls. In this study, the structure and location of sunflower FAR proteins were determined. They were also expressed exogenously in Saccharomyces cerevisiae to evaluate their substrate specificity based on the fatty alcohols synthesized by the transformed yeasts. Three of the four enzymes tested showed activity in yeast. HaFAR3 produced C18, C20 and C22 saturated alcohols, whereas HaFAR4 and HaFAR5 produced C24 and C26 saturated alcohols. The involvement of these genes in the synthesis of sunflower seed wax esters was addressed by considering the results obtained.

Asymmetric Synthesis of Saturated and Unsaturated Hydroxy Fatty Acids (HFAs) and Study of Their Antiproliferative Activity.

Hydroxy fatty acids (HFAs) constitute a class of lipids, distinguished by the presence of a hydroxyl on a long aliphatic chain. This study aims to expand our insights into HFA bioactivities, while also introducing new methods for asymmetrically synthesizing unsaturated and saturated HFAs. Simultaneously, a procedure previously established by us was adapted to generate new HFA regioisomers. An organocatalytic step was employed for the synthesis of chiral terminal epoxides, which either by alkynylation or by Grignard reagents resulted in unsaturated or saturated chiral secondary alcohols and, ultimately, HFAs. 7-(S)-Hydroxyoleic acid (7SHOA), 7-(S)-hydroxypalmitoleic acid (7SHPOA) and 7-(R)- and (S)-hydroxymargaric acids (7HMAs) were synthesized for the first time and, together with regioisomers of (R)- and (S)-hydroxypalmitic acids (HPAs) and hydroxystearic acids (HSAs), whose biological activity has not been tested so far, were studied for their antiproliferative activities. The unsaturation of the long chain, as well as an odd-numbered (C17) fatty acid chain, led to reduced activity, while the new 6-(S)-HPA regioisomer was identified as exhibiting potent antiproliferative activity in A549 cells. 6SHPA induced acetylation of histone 3 in A549 cells, without affecting acetylated α-tubulin levels, suggesting the selective inhibition of histone deacetylase (HDAC) class I enzymes, and was found to inhibit signal transducer and activator of transcription 3 (STAT3) expression.

Borrowing hydrogen C-alkylation with secondary saturated heterocyclic alcohols.

The borrowing hydrogen methodology (BH) has emerged as a powerful tool for the rapid construction of C-C bonds, offering a greener alternative to traditional multi-step syntheses. This methodology involves the activation of inactivated alcohols followed by condensation or aldolization, ultimately leading to the regeneration of the saturated product. Herein, we report the C-alkylation of a hindered ketone with challenging secondary saturated heterocyclic alcohols. Our study encompasses the optimization of reaction conditions using either an iridium or a ruthenium catalyst and exploration of substrate scope. We demonstrate the efficient synthesis of substituted pyrrolidines and piperidines directly from a triol precursor, showcasing the versatility of this methodology. Moreover, we illustrate the post-functionalization of BH products, significantly broadening their chemical utility.

Adaptation of the maize seedling seminal roots to srought: Essential role of plasma membrane H+-ATPases activity

To understand how maize plants adapt to drought, this study examines the role of plasma membrane proton pumps in root growth. This study delves into the physiological mechanisms through which maize plants respond to drought conditions, with a particular emphasis on elucidating the crucial role played by plasma membrane proton pumps in facilitating adaptive changes in root growth. Our results underscore the indispensable nature of these pumps in orchestrating precise modulation of root growth patterns during drought stress, highlighting their profound significance in stress responses. Additionally, the study reveals that osmotic stress alters lipid profiles in the plasma membrane, potentially impacting its functioning and the activity of membrane proteins. To understand the role of plasma membrane (PM) H<sup>+</sup>-ATPases in the adaptative response to osmotic stress and in the regulation of root growth in maize, we studied the gene expression and enzyme activity of PM H<sup>+</sup>-ATPases, as well as the changes in plant biomass and total root growth, in the seedlings of two maize cultivars: the drought-tolerant Calo cultivar and the drought-sensitive Abelardo. The seedlings were exposed to simulated drought for 24 h (treatment with 20% PEG). The enzyme activity and gene expression of the <i>MHA4</i> H<sup>+</sup>-ATPase increased in the Calo variety but declined in Abelardo plants treated with PEG. The growth of roots in Abelardo plants exposed to 24 h of PEG treatment was reduced to almost 50% of the control. Conversely, for the Calo cultivar, there was no remarkable morpho-physiological difference between the roots of stressed and non-stressed plants. Therefore, the activity of the PM H<sup>+</sup>-ATPase seems to be an important factor for proper root growth during the adaptation of maize to drought. In addition, osmotic stress also induced changes in the levels of saturated polyisoprenoid alcohols in the plasma membrane fraction of maize roots. The increased levels of this class of lipids might modulate the physico-chemical properties of the PM lipid bilayer and thus affect its functioning and modify the activity of membrane proteins, such as PM H<sup>+</sup>-ATPases.

Understanding fundamental effects of biofuel structure on ignition and physical fuel properties

The development of biochemicals and biofuels with advantaged properties of higher combustion efficiency at lower emission levels can be aided by a priori prediction of critical global characteristics based on molecular structure. Existing predictive techniques are incomplete for comprehensive ignition and physical fuel property prediction. This investigation focuses on filling this knowledge gap by developing a priori prediction techniques for predicting important ignition as well as physical fuel properties of promising advantaged biofuels. We demonstrate the utility of this a priori prediction technique on saturated (≤C5) alcohols, both linear and branched in nature by correlating their molecular structure with both important ignition and physical properties of the fuels. This work utilizes a semi-automated method of predicting ignition characteristics via accurate fundamental-based calculations of the fuel radical cascades that govern low-temperature combustion. This numerical methodology is supported by the relevant fuel ignition delay time (IDT) and research octane number (RON) data experimentally measured by the Advanced Fuel Ignition Delay Analyzer (AFIDA). Phyiscal fuel property trends are also analyzed by correlating the molecular structure of the fuel to its physical characteristics. Based on their molecular structure, recommendations are made on an a priori method for selecting biofuels that have advantaged properties for the selected fuel application. Lastly, the utility of this investigation is extended beyond the subset of alcohols considered by analyzing the IDT trends of i-Pentanol and n-Hexanol, revealing the fidelity of the novel kinetic modelling approach and the accuracy of the predicted trends in this study.

Oxidative Cleavage of C−C Bonds in Non‐aromatic Oxygenates with Molecular Oxygen for Synthesis of Carboxylic Acids

AbstractOxidative carbon‐carbon cleavage reactions of non‐aromatic oxygenates such as vicinal diols are reviewed. In comparison with aromatic oxygenates where the benzyl positions are easily oxidized, non‐aromatic alcohols are difficult to be oxidized. The use of excess base in combination with metal catalysts is a typical approach, and the oxidations of 1,2‐cyclohexanediol and dihydroxylated derivatives of oleic acid have been reported with good yields of (di)carboxylate. Oxidation under acidic conditions typically uses vanadium as a key component of catalyst. Vanadium alone is active in oxidation of hydroxyketones and not effective in oxidation of saturated alcohols and polyols. Oxidation of sugars to formic acid is catalyzed by vanadium. For the oxidation of vicinal diols, the combination of platinum and vanadium is effective. There are some recently‐discovered systems for carbon‐carbon dissociation reactions of 1,2‐difunctionalized compounds, such as 2‐methoxycyclohexanone oxidation to adipic acid with polyoxometalate catalysts. On the other hand, the progress of research in the oxidation of cyclohexanone to adipic acid, which is an important industrial process, is less rapid, and we commented on the situation.