Benzylation of Alcoholic Hydroxyl Groups with Benzyl Mesylate by Using a Catalytic Amount of Lithium Tetrakis(pentafluorophenyl)borate in the Coexistence of Lithium Triflate and Magnesium Oxide

2000 ◽  
Vol 29 (12) ◽  
pp. 1352-1353 ◽  
Author(s):  
Masakazu Nakano ◽  
Jun-ichi Matsuo ◽  
Teruaki Mukaiyama
Keyword(s):  
Magnesium Oxide ◽  
Catalytic Amount ◽  
Hydroxyl Groups ◽  
Lithium Triflate ◽  
Alcoholic Hydroxyl

scholarly journals Titanium Dioxide Modified with Alcoholic Hydroxyl Groups

1994 ◽  
Vol 67 (8) ◽  
pp. 489-495 ◽  
Author(s):  
Tsuneo SUHARA ◽  
Hiroshi HUKUI ◽  
Michihiro YAMAGUCHI
Keyword(s):  
Titanium Dioxide ◽  
Hydroxyl Groups ◽  
Alcoholic Hydroxyl

Convenient preparation of a β-O-4-type lignin model trimer via KOH-catalyzed hydroxymethylation and a new protection method

Holzforschung ◽  
2013 ◽  
Vol 67 (2) ◽  
pp. 129-136 ◽  
Author(s):  
Maarit Lahtinen ◽  
Anssi Haikarainen ◽  
Jussi Sipilä
Keyword(s):  
Model Compound ◽  
Catalytic Amount ◽  
Side Chain ◽  
Hydroxyl Groups ◽  
Chemical Behavior ◽  
Model Compounds ◽  
Protection Method ◽  
Convenient Synthesis ◽  
Lignin Model ◽  
Convenient Preparation

Abstract Lignin, as the second most abundant biopolymer on earth, is one of the targets for plant biorefinery studies. Its complex chemical behavior is frequently studied by dimeric, trimeric, etc. model compounds, preferably with a β-O-4-type structure. In the present study, a convenient synthesis of a β-O-4-type trimeric model compound possessing a free syringylic hydroxyl has been investigated. Two key modifications were in focus: (1) Protection of the aliphatic hydroxyl groups of the starting phenolic dimer prior to the SN2 displacement reaction before introducing the syringylic moiety with 2,2-dimethoxypropane. (2) The hydroxymethylation step to introduce the full side chain moiety. When this reaction was performed in dioxane/water in the presence of a catalytic amount of KOH instead of K2CO3, the formation of a side product via dehydration was markedly reduced. In addition, a convenient method for introducing an α,β-epoxide structure in acetophenone is recommended.

scholarly journals Magnetic Fe3O4@silica sulfuric acid nanoparticles promoted regioselective protection/deprotection of alcohols with dihydropyran under solvent-free conditions

RSC Advances ◽  
2017 ◽  
Vol 7 (89) ◽  
pp. 56559-56565 ◽  
Author(s):  
Kalyani Rajkumari ◽  
Juri Kalita ◽  
Diparjun Das ◽  
Lalthazuala Rokhum
Keyword(s):  
Sulfuric Acid ◽  
Sulphuric Acid ◽  
Catalytic Amount ◽  
Solvent Free ◽  
Hydroxyl Groups ◽  
Silica Sulfuric Acid ◽  
Solvent Free Conditions ◽  
Magnetic Fe3o4

Protection (and deprotection) of hydroxyl groups via tetrahydropyranylation was carried out effectively using a catalytic amount of Fe3O4 supported silica sulphuric acid nanoparticles (Fe3O4@SiO2@SO3H) under solvent-free conditions.

Chemical Characteristics of Humic Compounds Isolated From Some Decomposed Marine Algae

1972 ◽  
Vol 29 (1) ◽  
pp. 55-60 ◽  
Author(s):  
M. A. Rashid ◽  
A. Prakash
Keyword(s):  
Molecular Weight ◽  
Fulvic Acids ◽  
Structural Features ◽  
Hydroxyl Groups ◽  
Laminaria Digitata ◽  
Carbon And Nitrogen ◽  
Humic Compounds ◽  
Spectroscopic Characteristics ◽  
Nitrogen Contents ◽  
Alcoholic Hydroxyl

The chemical and spectroscopic characteristics of humic compounds isolated from decomposed thalli of Fucus vesiculosus and Laminaria digitata, seaweed exudate, and dissolved organic matter in river water show that, in spite of several differences, their gross structural features are similar to those of humic compounds isolated from marine sediments or soils. Dominant functional groups are carboxyl and carbonyl but phenolic and alcoholic hydroxyl groups are also present in small proportions. Between 20 and 40% of humic acids are represented by fractions having molecular weight greater than 200,000, whereas the fulvic acids do not exceed 10,000. Carbon and nitrogen contents show a direct relation with molecular weight whereas the oxygen is inversely related.

scholarly journals Preparation of MgO nanocrystals and catalytic mechanism on phenol ozonation

RSC Advances ◽  
2017 ◽  
Vol 7 (69) ◽  
pp. 43464-43473 ◽  
Author(s):  
Bing Wang ◽  
Xingaoyuan Xiong ◽  
Hongyang Ren ◽  
ZhiYu Huang
Keyword(s):  
Activation Energy ◽  
Magnesium Oxide ◽  
Catalytic Mechanism ◽  
Hydroxyl Groups ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups ◽  
Ozonation Process

The prepared magnesium oxide catalyzes the ozonation process using its surface hydroxyl groups alone, and does not involve a change of activation energy.

Quantitative nitration of alcoholic hydroxyl groups

1967 ◽  
Vol 39 (14) ◽  
pp. 1795-1799 ◽  
Author(s):  
George H. Schenk ◽  
Milagros. Santiago
Keyword(s):  
Hydroxyl Groups ◽  
Alcoholic Hydroxyl

Studies on the Lignin of Eucalyptus regnans. II. The Nature of the Hydroxyl Groups and the Presence of the Carbonyl Group in Thiolignin

1948 ◽  
Vol 1 (2) ◽  
pp. 241
Author(s):  
JWT Merewether
Keyword(s):  
Benzoyl Chloride ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Carbonyl Groups ◽  
Eucalyptus Regnans ◽  
Trimethyl Ether ◽  
Free Hydroxyl ◽  
Active Methylene ◽  
Methylene Group ◽  
Alcoholic Hydroxyl

E. regnans thiolignin reacts with p-toluenesulphonyl chloride in pyridine to form a hexatosyl derivative ; its trimethyl ether reacts likewise to form a tritosyl derivative. Both compounds still have a free hydroxyl group which can be acetylated. Similarly they yield a hexabenzoate and tribenzoate respectively by the Schotten-Baumann reaction, but in pyridine, thiolignin reacts with benzoyl chloride to give a heptabenzoate and trimethylthiolignin a tetrabenzoate. No reaction takes place when trimethyl thiolignin is treated with triphenylchloromethane in pyridine. The above data are interpreted as evidence that of the four alcoholic hydroxyl groups three are secondary and one tertiary. With phenylhydrazine, thiolignin yields a phenylosazone ; with p-nitrophenylhydrazine it yields a p-nitrophenylhydrazone. On the other hand, trimethylthiolignin does not react with phenylhydrazine, indicating the absence of non-enolizable carbonyl groups. Thiolignin condenses with benzaldehydes indicating the presence of an active methylene group. From this evidence it is deduced that the grouping CH2-CO-CHOH- is present.

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