Isopropylidenation of L-arabinose N,N-dimethylhydrazone

1985 ◽  
Vol 50 (9) ◽  
pp. 1994-1999 ◽  
Author(s):  
Miroslav Koóš ◽  
Harry S. Mosher
Keyword(s):  
Sulfuric Acid ◽  
High Yield ◽  
Cannizzaro Reaction ◽  
Branched Chain

Direct isopropylidenation of L-arabinose N,N-dimethylhydrazone (I) was studied. Four major products whose structures were proven were produced in varying ratios depending upon the conditions. 2,2-Dimethoxypropane and sulfuric acid at 20 °C gave a 36% yield of 2,3:4,5-di-O-isopropylidene-L-arabinose N,N-dimethylhydrazone (II). Attempted aldol condensations directly on this hydrazone with paraformaldehyde were unsuccessful. This hydrazone was readily hydrolyzed to the corresponding protected aldehyde VI which underwent an aldol-Cannizzaro reaction to give the branched chain pentitol VII in high yield.

scholarly journals Catalytic condensation of phenol with formaldehyde into BPF on recyclable anchoring sulfuric acid

2020 ◽  
Vol 213 ◽  
pp. 01003
Author(s):  
Hui Li ◽  
Xi Cao ◽  
Huiting He ◽  
Jian Liu ◽  
Weijian Xiang ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Catalytic Performance ◽  
Significant Loss ◽  
High Yield ◽  
Element Analysis ◽  
Simple Filtration ◽  
Ft Ir ◽  
The Mind

A novel solid-acid catalyst (PVC-EDA-SO4H) based on polyvinyl chloride (PVC) were prepared after amination of Ethylenediamine (EDA) and anchorage of sulfuric acid. The as-prepared catalyst was characterized by FT-IR, Element analysis, Chemical titration and Thermal analysis, the results indicated that the sulfuric acid was successfully anchored on PVC. The PVC-EDA-SO4H showed excellent catalytic performance for the synthesis of bisphenol F, and achieved almost high yield and selectivity (94%) of BPF under the mind reaction conditions. Meanwhile, exhibited excellent reusability without the significant loss after six cycles via simple filtration.

scholarly journals Wastewater Minimization in Indirect Electrochemical Synthesis of Phenylacetaldehyde

2002 ◽  
Vol 2 ◽  
pp. 48-52 ◽  
Author(s):  
Zhirong Sun ◽  
Xiang Hu ◽  
Ding Zhou
Keyword(s):  
Sulfuric Acid ◽  
Current Efficiency ◽  
Electrochemical Oxidation ◽  
Acid Concentration ◽  
Electrochemical Synthesis ◽  
Chemical Process ◽  
Sulfuric Acid Concentration ◽  
High Yield ◽  
High Current ◽  
High Current Efficiency

Wastewater minimization in phenylacetaldehyde production by using indirect electrochemical oxidation of phenylethane instead of the seriously polluting traditional chemical process is described in this paper. Results show that high current efficiency of Mn(III) and high yield of phenylacetaldehyde can be obtained at the same sulfuric acid concentration (60%). The electrolytic mediator can be recycled and there will be no waste discharged.

New Route to Branched-chain Aminodeoxy Sugars by Reaction of Ketoses with Acetonitrile. Synthesis of Methyl 3-C-2′-Aminoethyl-2-deoxy-α-D-arabino-hexopyranoside

1974 ◽  
Vol 52 (1) ◽  
pp. 51-54 ◽  
Author(s):  
Alex Rosenthal ◽  
G. Schöllnhammer
Keyword(s):  
Catalytic Hydrogenation ◽  
Liquid Ammonia ◽  
High Yield ◽  
Lithium Amide ◽  
Branched Chain

Addition of methyl 4,6-O-benzylidene-2-deoxy-α-D-erythro-hexopyranosid-3-ulose (1) to acetonitrile in liquid ammonia at −50 to −60° in the presence of lithium amide gave, in high yield, crystalline methyl 4,6-O-benzylidene-3-C-cyanomethyl-2-deoxy-α-D-arabino-hexopyranoside (2) exclusively. The proof of structure 2 is described. Debenzylidenation of 2 afforded the branched-chain cyano glycoside 3. Compound 3 was converted into its 3,4,6-tri-O-acetate (8) and 4,6-di-O-p-nitrobenzoate (9) derivatives. Catalytic hydrogenation of 3 over rhodium on alumina yielded methyl 3-C-2′-aminoethyl-2-deoxy-α-D-arabino-hexopyranoside which was characterized as its N-2,4-dinitrophenyl derivative (7).

scholarly journals A Fast, Highly Efficient, and Green Protocol for Synthesis of Biscoumarins Catalyzed by Silica Sulfuric Acid Nanoparticles as a Reusable Catalyst

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Bahareh Sadeghi ◽  
Tayebe Ziya
Keyword(s):  
Sulfuric Acid ◽  
Aromatic Aldehyde ◽  
High Yield ◽  
Reusable Catalyst ◽  
Silica Sulfuric Acid ◽  
Green Protocol ◽  
Highly Efficient

Silica sulfuric acid nanoparticles have been prepared and shown to efficiently catalyse the reaction between an aromatic aldehyde or phenylglyoxal and a 4-hydroxycoumarin at reflux in EtOH to afford the biscoumarin derivatives in high yield.

scholarly journals Metabolomic analysis of biosynthesis mechanism of ε-polylysine produced by Streptomyces diastatochromogenes

2020 ◽  
Author(s):  
Ziyuan Wang ◽  
Fengzhu Guo ◽  
Tianyu Dong ◽  
Zhilei Tan ◽  
Mohamed Abdelraof ◽  
...  
Keyword(s):  
Metabolic Regulation ◽  
Absorption Capacity ◽  
High Yield ◽  
Regulation Mechanism ◽  
Original Strain ◽  
Metabolomic Analysis ◽  
Streptomyces Sp ◽  
Activity Of Enzymes ◽  
The Difference ◽  
Branched Chain

Abstract ε-polylysine (ε-PL) is a polypeptide that shows broad-spectrum inhibition against both Gram-positive and Gram-negative bacteria, and it’s mainly produced by Streptomyces sp. However, the biosynthesis mechanism of ε-PL by Streptomyces sp. is still unclear. Herein, the metabolomic analysis of the biosynthesis mechanism of ε-PL in the original strain TUST and the high-yield mutant strain 6#-7 were investigated. Results show that the difference on metabolisms between TUST and 6#-7 was significant during fermentation periods. And based on further analyses of the results of both metabolomics and enzymatic activity, a possible metabolic regulation mechanism of the high-yield mutagenized strain 6#-7 was proposed. The transport and absorption capacity for glucose of strain 6#-7 is improved. And the activity of enzymes relating to ε-PL synthesis, including Hexokinase (HK) et al., is strengthened. On the contrary, the activity of enzymes in the branched-chain pathways, such as Succinate dehydrogenase (SDH) et al. is decreased. Meanwhile, the increase of trehalose, glutamic acid and proline makes the strain 6#-7 more resistant to ε-PL. Moreover, the strain 6#-7 has stronger ability to transfer ε-PL out the cell. Thus the ability of the mutagenized strain to synthesize ε-PL is enhanced and the strain 6#-7 can produce more ε-PL compared with the original strain. These findings provide a theoretical basis for further improving the production of ε-PL.

scholarly journals Metabolomic Analysis of Biosynthesis Mechanism of ε-Polylysine Produced by Streptomyces diastatochromogenes

2021 ◽  
Vol 9 ◽  
Author(s):  
Ziyuan Wang ◽  
Fengzhu Guo ◽  
Tianyu Dong ◽  
Zhilei Tan ◽  
Mohamed Abdelraof ◽  
...  
Keyword(s):  
Metabolic Regulation ◽  
Absorption Capacity ◽  
High Yield ◽  
Regulation Mechanism ◽  
Original Strain ◽  
Metabolomic Analysis ◽  
Homoserine Dehydrogenase ◽  
Yield Strain ◽  
The Difference ◽  
Branched Chain

ε-Polylysine (ε-PL), a natural preservative with broad-spectrum antimicrobial activity, has been widely used as a green food additive, and it is now mainly produced by Streptomyces in industry. In the previous study, strain 6#-7 of high-yield ε-PL was obtained from the original strain TUST by mutagenesis. However, the biosynthesis mechanism of ε-PL in 6#-7 is still unclear. In this study, the metabolomic analyses of the biosynthesis mechanism of ε-PL in both strains are investigated. Results show that the difference in metabolisms between TUST and 6#-7 is significant. Based on the results of both metabolomic and enzymatic activities, a metabolic regulation mechanism of the high-yield strain is revealed. The transport and absorption capacity for glucose of 6#-7 is improved. The enzymatic activity benefits ε-PL synthesis, such as pyruvate kinase and aspartokinase, is strengthened. On the contrary, the activity of homoserine dehydrogenase in the branched-chain pathways is decreased. Meanwhile, the increase of trehalose, glutamic acid, etc. makes 6#-7 more resistant to ε-PL. Thus, the ability of the mutagenized strain 6#-7 to synthesize ε-PL is enhanced, and it can produce more ε-PLs compared with the original strain. For the first time, the metabolomic analysis of the biosynthesis mechanism of ε-PL in the high-yield strain 6#-7 is investigated, and a possible mechanism is then revealed. These findings provide a theoretical basis for further improving the production of ε-PL.

The Chemistry of Sugar-Cane Wax. I. The Nature of Sugar-Cane Wax

1960 ◽  
Vol 13 (2) ◽  
pp. 261 ◽  
Author(s):  
JA Lamberton ◽  
AH Redcliffe
Keyword(s):  
Sugar Cane ◽  
Aldol Condensation ◽  
Conclusive Evidence ◽  
High Yield ◽  
Reduced Pressure ◽  
Polymeric Form ◽  
Cannizzaro Reaction ◽  
Long Chain

Distillation of sugar-cane cuticle wax under reduced pressure gives a high yield of long-chain aldehydes, which are considered to occur in the wax in polymeric form. The products obtained from the wax under normal saponification conditions are apparently produced from the aldehydes by a Cannizzaro reaction, and by aldol condensation with subsequent dehydration. The cuticle wax also contains hydrocarbons and free alcohols and acids, but there is no conclusive evidence for the presence of esters.

Separation of Pesticide Residues from Lipids Prior to Gas-Liquid Chromatographic Analysis

1976 ◽  
Vol 59 (1) ◽  
pp. 224-225
Author(s):  
Robert Lea
Keyword(s):  
Sulfuric Acid ◽  
Petroleum Ether ◽  
Sodium Hydroxide ◽  
Pesticide Residues ◽  
Chromatographic Analysis ◽  
High Yield ◽  
Chicken Fat ◽  
Dilute Sulfuric Acid ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic

Abstract Lipids are separated from dieldrin, endrin, and p,p′-DDE residues by saponification in ethanolic sodium hydroxide, acidification with dilute sulfuric acid, and adsorption chromatography on deactivated alumina, using petroleum ether as the eluant. Dieldrin, endrin, and p,p′-DDE are efficiently recovered (95–102%), and p,p′-DDT is converted to p,p′-DDE, which is then recovered with high yield (90–96%). Extremely low lipid carryover (<0.3–0.5%) is observed for 0.5–1.0 g samples of chicken fat.

scholarly journals Benzenesulfonic Acid - an Green Efficient Esterification Catalysts for Continuous Synthesis of n-propyl Acetate

2021 ◽  
Vol 72 (2) ◽  
pp. 94-101
Author(s):  
Zhijun Xia
Keyword(s):  
Sulfuric Acid ◽  
High Yield ◽  
Benzenesulfonic Acid ◽  
Propyl Acetate ◽  
Comparison System ◽  
Fast Evaluation ◽  
Green Catalyst ◽  
Continuous Synthesis ◽  
Continuous Rectification ◽  
The Stability

The esterification of acetic acid and n-propanol catalyzed by benzenesulfonic acid and its derivatives in the batch and continuous rectification tower was studied, in order to develop a new effective and green catalyst instead of the oxidative and corrosive sulfuric acid. A series of the comparison system with sulfuric acid was build for the targeted and fast evaluation of catalysts. The results showed that the catalytic esterification activity of p-phenolsulfonic acid and p-toluenesulfuric acid is very closed to sulfonic acid in the continuous rectification tower. Furthermore, the stability test for continuous esterification with p-toluenesulfuric acid presented that the high yield of n-propyl acetate could maintain 50 hours and stability. Therefore, p-phenolsulfonic acid and p-toluenesulfuric acid could be prospective substitutes for sulfuric acid for the continuous synthesis of n-propyl acetate in the rectification tower.

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