The Conversion of Levoglucosenone into Isolevoglucosenone

2015 ◽  
Vol 68 (4) ◽  
pp. 593 ◽  
Author(s):  
Xinghua Ma ◽  
Natasha Anderson ◽  
Lorenzo V. White ◽  
Song Bae ◽  
Warwick Raverty ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Acetic Acid ◽  
Single Crystal ◽  
Lignocellulosic Biomass ◽  
Allylic Alcohol ◽  
Allylic Alcohols ◽  
Alkaline Hydrogen Peroxide ◽  
X Ray ◽  
Epoxy Ketones ◽  
Epoxy Alcohols

Levoglucosenone (1), a compound that will soon be available in tonne quantities through the pyrolysis of acid-treated lignocellulosic biomass, has been converted into isolevoglucosenone (2) using Wharton rearrangement chemistry. Treatment of compound 1 with alkaline hydrogen peroxide gave the γ-lactones 5 and 6 rather than the required epoxy-ketones 3 and/or 4. However, the latter pair of compounds could be obtained by an initial Luche reduction of compound 1, electrophilic epoxidation of the resulting allylic alcohol 8 and oxidation of the product oxiranes 9 and 10. Independent treatment of compounds 3 and 4 with hydrazine then acetic acid followed by oxidation of the ensuing allylic alcohols finally afforded isolevoglucosenone (2). Details of the single-crystal X-ray analyses of epoxy-alcohols 9 and 10 are reported.

scholarly journals Crystallization and preliminary X-ray analysis of formate oxidase, an enzyme of the glucose–methanol–choline oxidoreductase family

2010 ◽  
Vol 66 (9) ◽  
pp. 1064-1066 ◽  
Author(s):  
Yoshifumi Maeda ◽  
Daiju Doubayashi ◽  
Takumi Ootake ◽  
Masaya Oki ◽  
Bunzo Mikami ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Peroxide ◽  
Single Crystal ◽  
Aspergillus Oryzae ◽  
Diffraction Data ◽  
Diffusion Method ◽  
Hanging Drop ◽  
Space Group ◽  
X Ray ◽  
Vapour Diffusion

Formate oxidase (FOD), which catalyzes the oxidation of formate to yield carbon dioxide and hydrogen peroxide, belongs to the glucose–methanol–choline oxidoreductase (GMCO) family. FOD fromAspergillus oryzaeRIB40, which has a modified FAD as a cofactor, was crystallized at 293 K by the hanging-drop vapour-diffusion method. The crystal was orthorhombic and belonged to space groupC2221. Diffraction data were collected from a single crystal to 2.4 Å resolution.

scholarly journals Isolation of Cellulose from Wheat Straw Using Alkaline Hydrogen Peroxide and Acidified Sodium Chlorite Treatments: Comparison of Yield and Properties

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Umair Qasim ◽  
Zulfiqar Ali ◽  
Muhammad Shahid Nazir ◽  
Sadaf Ul Hassan ◽  
Sikander Rafiq ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Wheat Straw ◽  
Environmental Concerns ◽  
Sodium Chlorite ◽  
X Ray Diffraction ◽  
Alkaline Hydrogen Peroxide ◽  
X Ray ◽  
Multifunctional Material ◽  
Hydrogen Peroxide Treatment ◽  
Ft Ir

Environmental concerns due to excessive use of synthetic or petroleum-based materials have encouraged scientists to develop novel, sustainable, and multifunctional material using abundant lignocellulosic biomass. In this work, a study was conducted on the isolation of cellulose from wheat straw using two different methods: acidified sodium chlorite and alkaline hydrogen peroxide. A comparative study was carried out based on the yield and properties of extracted cellulose. The final product (after treatments) was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) for the identification of properties. Both the treatments isolated pure white color cellulose. However, the yield of cellulose isolated through acidified sodium chlorite treatment (81.4%) was higher than alkaline hydrogen peroxide treatment (79%). Moreover, no huge difference was observed in the crystallinity and thermal properties of extracted cellulose.

Conformational Comparisons Between Phenoxyacetic Acid Derivatives in Adducts and in the Free Form

1999 ◽  
Vol 52 (7) ◽  
pp. 695 ◽  
Author(s):  
Graham Smith ◽  
Catherine J. Cooper ◽  
Veena Chauhan ◽  
Daniel E. Lynch ◽  
Simon Parsons ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Single Crystal ◽  
Free Acid ◽  
Molecular Complexes ◽  
The Other ◽  
Free Form ◽  
Phenoxyacetic Acid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dichlorophenoxy Acetic Acid

Six molecular complexes containing the herbicidally active (2,4-dichlorophenoxy)acetic acid (2,4-d) and (2,4,5-trichlorophenoxy)acetic acid (2,4,5-t) have been prepared and studied by using single-crystal X-ray diffraction techniques. These adduct structures are 2,4-d with 4,4′-dipyridine (2 : 1 complex), and 2,4,5-t with respectively 5-nitroquinoline (1 : 1), 4,4′-dipyridine (2 : 1), 2-amino-2-thiazoline (1 : 1), 2-aminobenzothiazole (1 : 1) and 2-amino-5-ethyl-1,3,4-thiadiazole (1 : 1). The conformations of the phenoxyacetic acid molecules were found to be either synclinal (in three cases) or antiperiplanar (in the other three cases). A general review is also made about the conformational aspects of previously reported adducts of phenoxyacetic acid derivatives and how they compare to their free acid structures.

Baeyer-Villiger Oxidation of 10-Methyl-9-Anthraldehyde: Formation and Photochemical Dimerization of 9-Formyloxy-10-methylanthracene

1988 ◽  
Vol 41 (12) ◽  
pp. 1977 ◽  
Author(s):  
HD Becker ◽  
BW Skelton ◽  
AB Turner ◽  
AH White
Keyword(s):  
Molecular Structure ◽  
Hydrogen Peroxide ◽  
Acetic Acid ◽  
Sulfuric Acid ◽  
Diffraction Study ◽  
Crystalline State ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tail Structure ◽  
Villiger Oxidation

Oxidation of 10-methyl-9-anthraldehyde with hydrogen peroxide in acetic acid in the presence of sulfuric acid gives 9-formyloxy-10-methylanthracene which dimerizes in solution upon exposure to light. The head-to-tail structure of the 4π+4π photodimer was established by a single-crystal X-ray diffraction study. In the crystalline state, the molecular structure is centrosymmetric, and the length of the photochemically formed bonds 1.646(4)Ǻ. Crystals are monoclinic, P21/c, a 7.980(5), b 16.143(7), c 9.571(3)Ǻ, β 114.38(3)°, Z=2 dimers; R was 0.041 for 1362 'observed' diffractometer reflections.

scholarly journals Structural Study of Three 1,2,4-triazole Derivatives Prepared by Oxidative Cyclization of Thiosemicarbazides

Proceedings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 20
Author(s):  
Mirian Artime ◽  
Alfonso Castiñeiras ◽  
Isabel García-Santos ◽  
Manuel Saa
Keyword(s):  
Acetic Acid ◽  
Single Crystal ◽  
Structural Study ◽  
Supramolecular Assembly ◽  
Oxidative Cyclization ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Triazole Derivatives

In the present research, 5,5-dimethyl-4-phenyl-4,5-dihydro-3H-1,2,4-triazole-3-thione (1) was prepared by condensation from N-phenylhydrazinecarbothioamide, while 4-phenyl-5-(pyrazin-2-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (2) and 2-((5-(pyridin-2-yl) -4H-1,2,4-triazol-3-yl)thio)acetic acid (3) was prepared by oxidative cyclization from 2-(amino(pyrazin-2-yl)methylene)-N-phenylhydrazine-1-carbothioamide and 2-(amino(pyridine-2-yl)methylene)hydrazine-1-carbothioamide, respectively. The three compounds have been well characterized and their molecular structures studied by single-crystal X-ray diffraction. The supramolecular assembly of each crystal has also been analyzed and discussed.

Enhancement of lignocellulosic biomass anaerobic digestion by optimized mild alkaline hydrogen peroxide pretreatment for biorefinery applications

2021 ◽  
Vol 298 ◽  
pp. 113539
Author(s):  
İbrahim Alper Başar ◽  
Özge Çoban ◽  
Mehmet Yekta Göksungur ◽  
Çiğdem Eskicioğlu ◽  
Nuriye Altınay Perendeci
Keyword(s):  
Hydrogen Peroxide ◽  
Anaerobic Digestion ◽  
Lignocellulosic Biomass ◽  
Alkaline Hydrogen Peroxide

Pigments of Fungi. XXIII. Approaches Towards (±)-Austrocortirubin From 3-Methyl-1-trimethylsilyloxybuta-1,3-diene

1991 ◽  
Vol 44 (12) ◽  
pp. 1715 ◽  
Author(s):  
CJ Burns ◽  
M Gill ◽  
AH Binothman ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Structure Analysis ◽  
X Ray ◽  
Epoxy Alcohols

The products (5) and (21) of cycloaddition between 3-methyl-1-trimethylsilyloxybuta-1,3-diene (3) and naphthazarin (4), and between (3) and the naphthopurpurin acetal (2), respectively, are converted into the tetrahydroanthraquinones (16)-(18), (26) and (27) via a series of intermediate epoxy alcohols. Stereochemical assignments are corroborated by a single-crystal X-ray structure analysis of the bromohydrin (16). The tetrahydroanthraquinones (27) and (18), advanced intermediates in a proposed synthesis of the fungus pigment austrocortirubin (1) and its 6-demethoxy analogue (20), respectively, are resistant to efficient dehalogenation.

Stereoselective Synthesis of (±)-(cis-6-Methyltetrahydropyran-2-yl)acetic Acid

1994 ◽  
Vol 47 (9) ◽  
pp. 1735 ◽  
Author(s):  
P Varelis ◽  
AJ Graham ◽  
BL Johnson ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Acetic Acid ◽  
Single Crystal ◽  
Title Compound ◽  
Stereoselective Synthesis ◽  
Relative Configuration ◽  
X Ray

The title compound (1) has been synthesized in seven steps and in 42% overall yield from the nucleophilic diene (2). The relative configuration of (1) has been confirmed by a single-crystal X-ray study.

Alkaline hydrogen peroxide pretreatment of lignocellulosic biomass: status and perspectives

2017 ◽  
Vol 8 (1) ◽  
pp. 225-234 ◽  
Author(s):  
Emmanuel Damilano Dutra ◽  
Fernando Almeida Santos ◽  
Bárbara Ribeiro Alves Alencar ◽  
Alexandre Libanio Silva Reis ◽  
Raquel de Fatima Rodrigues de Souza ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Lignocellulosic Biomass ◽  
Alkaline Hydrogen Peroxide

Molecular Cocrystals of Carboxylic Acids. XXXI Adducts of 2-Aminopyrimidine and 3-Amino-1,2,4-triazole with Heterocyclic Carboxylic Acids

1998 ◽  
Vol 51 (5) ◽  
pp. 403 ◽  
Author(s):  
Daniel E. Lynch ◽  
Tariq Latif ◽  
Graham Smith ◽  
Karl A. Byriel ◽  
Colin H. L. Kennard ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Carboxylic Acid ◽  
Single Crystal ◽  
Carboxylic Acids ◽  
Powder Diffraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Indole 3 Acetic Acid ◽  
Molecular Adducts

A series of molecular adducts of 2-aminopyrimidine and 3-amino-1,2,4-triazole with heterocyclic carboxylic acids have been prepared and characterized by using X-ray powder diffraction and in four cases by single-crystal X-ray diffraction methods. These four compounds are the (1 : 1) adducts of 2-aminopyrimidine with indole-3-acetic acid [(C4H5N3)(C10H9NO2)], N-methylpyrrole-2-carboxylic acid [(C4H5N3)(C6H7NO2)] and thiophen-2-carboxylic acid [(C4H5N3)(C5H4O2S)], and the (1 : 1) adduct of 3-amino-1,2,4-triazole with thiophen-2-carboxylic acid [(C2H4N4)(C5H4O2S)]. Other compounds described are the (1 : 1) adducts of 3-amino-1,2,4-triazole with indole-3-acetic acid and N-methylpyrrole-2-carboxylic acid.

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