SYNTHESIS OF VERATROYL ACETALDEHYDE AND INFLUENCE OF A HYDROXYL GROUP ON THE REACTIVITY OF THE PARA-CARBONYL GROUP

1941 ◽  
Vol 19b (1) ◽  
pp. 24-33 ◽  
Author(s):  
Leo Brickman ◽  
W. Lincoln Hawkins ◽  
Harold Hibbert
Keyword(s):  
Carbonyl Group ◽  
Theoretical Explanation ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Group ◽  
Methods Of Synthesis

Attempts, by three independent methods of synthesis, to prepare vanilloyl acetaldehyde are described. In each case it has been shown that the presence of a para phenolic hydroxyl group either prevents or alters the normal course of the reactions. The synthesis of veratroyl acetaldehyde has been accomplished, and this product is described. A theoretical explanation for the mutual interrelationship of the carbonyl and para phenolic hydroxyl group is suggested.

The Influence of Anthraquinone in Sulfite Delignification of Norway Spruce. 2. Phenolic Hydroxyl Group Formation

Holzforschung ◽  
1994 ◽  
Vol 48 (s1) ◽  
pp. 140-145 ◽  
Author(s):  
Hsin-Tai Chen ◽  
Masamitsu Funaoka ◽  
Yuan-Zong Lai
Keyword(s):  
Norway Spruce ◽  
Group Formation ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Group

Aqueous Medium Radical Addition to Ketimines with a Phenolic Hydroxyl Group

Synlett ◽  
2004 ◽  
Vol 2004 (14) ◽  
pp. 2597-2599 ◽  
Author(s):  
Yoshiji Takemoto ◽  
Hideto Miyabe ◽  
Yousuke Yamaoka
Keyword(s):  
Aqueous Medium ◽  
Radical Addition ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Group

Methylation of Phenolic Hydroxyl Group and Demethylation of Anisoles

2009 ◽  
Vol 2009 (4) ◽  
pp. 229-230 ◽  
Author(s):  
Nobuhiro Sato ◽  
Hiroyuki Endo
Keyword(s):  
Microwave Heating ◽  
Room Temperature ◽  
Reverse Reaction ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Phenolic Hydroxyl Groups ◽  
Phenyl Ethers ◽  
Methyl Phenyl

A mild methylation of phenolic hydroxyl groups with iodomethane was enabled in the presence of sodium bis(trimethylsilyl)amide at room temperature. The reverse reaction, namely demethylation of methyl phenyl ethers, was easily achieved by microwave heating with neat iodotrimethylsilane.

scholarly journals SYNTHESIS, IN VITRO ANTIOXIDANT AND ANTIMICROBIAL EVALUATION OF 3-HYDROXY CHROMONE DERIVATIVES

2018 ◽  
Vol 11 (3) ◽  
pp. 259
Author(s):  
Pallavi Kamble ◽  
Sailesh Wadher
Keyword(s):  
Antioxidant Activity ◽  
Double Bond ◽  
Antifungal Activity ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Group ◽  
Antibacterial And Antifungal Activity ◽  
Activity Data ◽  
Group 4 ◽  
Antibacterial And Antifungal

 Objective: The objective of the present study was to synthesize a series of 3-hydroxychromone derivatives and to evaluate its in vitro antioxidant and antimicrobial activities.Methods: 3-hydroxy chromones were synthesized using an algar flynn oyamada method which includes oxidative cyclization of 2-hydroxy chalcones in basic solution by hydrogen peroxide. 2-hydroxy chalcones were synthesized by Claisen-Schmidt condensation of substituted 2-hydroxy acetophenones with substituted aromatic aldehydes using polyethylene glycol-400 as a recyclable solvent. The synthesized compounds were evaluated for in vitro antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay. In addition, these compounds were also screened for in vitro antibacterial and antifungal activity by agar cup method and Poison plate method, respectively.Results: The structures of the synthesized compounds were characterized by infrared, 1H nuclear magnetic resonance and mass spectroscopy. The antioxidant activity data revealed that all the synthesized derivatives exhibited good activity due to the presence of phenolic hydroxyl group, 4-oxo group and 2,3-double bond. Further, the activity increased with the introduction of a more phenolic hydroxyl group and adjacent methoxy group in the structure. The antimicrobial activity data showed that the compounds possess better antibacterial and antifungal activity which is attributed to the presence of phenolic hydroxyl group and 4-oxo group in the structure.Conclusions: The use of inexpensive, eco-friendly and readily available reagents, easy work-up and high purity of products makes the procedure a convenient and robust method for the synthesis of title compounds. The presence of phenolic hydroxyl group, 4-oxo group, and 2,3-double bond in the structure is responsible for their good antioxidant and antimicrobial activities.

2-Substituted and 2,6-disubstituted 1,4-benzoquinone 4-oximes ('p-nitrosophenols')

1969 ◽  
Vol 22 (5) ◽  
pp. 935 ◽  
Author(s):  
RK Norris ◽  
S Sternhell
Keyword(s):  
Hydrogen Bonding ◽  
Physical Properties ◽  
Intramolecular Hydrogen Bonding ◽  
Tautomeric Equilibrium ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Group ◽  
Electronic Effects ◽  
Intramolecular Hydrogen

The preparation and physical properties of 27 compounds in the title series are described. Tautomerism, syn-anti isomerism, N.M.R. parameters, and the mechanism of isomerization are discussed. In this series of derivatives, the tautomeric equilibrium in dioxan solutions lies heavily towards the oxime form unless intramolecular hydrogen bonding between the substituent at C2 (or C6) and the phenolic hydroxyl group of the nitroso form is possible. The substituents at C2 (and C6) influence the position of the syn-anti equilibrium in the quinone monoxime forms through electronic effects.

Physical Stability and Lyophilization of Poly(ε-caprolactone)-b-Poly(ethyleneglycol)-b-Poly(ε-caprolactone) Micelles

2006 ◽  
Vol 6 (9) ◽  
pp. 3032-3039 ◽  
Author(s):  
Yong Hu ◽  
Yin Ding ◽  
Yuan Li ◽  
Xiqun Jiang ◽  
Changzheng Yang ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Carbonyl Group ◽  
Fluorescence Spectra ◽  
Physical Stability ◽  
Storage Period ◽  
Aqueous Dispersion ◽  
Hydroxyl Group ◽  
Core Shell ◽  
Ft Ir ◽  
The Stability

The stability and lyophilization of core–shell PCL-PEG-PCL micelles were investigated by fluorescence spectra, DLS, DSC, WAXD, and FT-IR. The prepared micelles were not stable when they were stored in aqueous dispersion under different condition. Their size increased in the first 20 days and decreased gradually when the storage period was extended. Lyophilization experiment showed that the cryoprotective agent (glucose) was an essential additive to protect the micelles from aggregating during the lyophilization process. After lyophilizing and re-dispersion, the PCL-PEG-PCL micelles became larger in size compared to as-prepared ones. DSC, WAXD, and IR measurements indicated the hydrogen bonding was formed between the hydroxyl group in glucose and the carbonyl group in PCL-PEG-PCL micelles. The effect of added glucose on protection of micelles from aggregation can be explained by the formation of hydrogen bonding with PCL-PEG-PCL micelles and the formation of solid glucose matrix.

ChemInform Abstract: HASHISH, IMPORTANCE OF THE PHENOLIC HYDROXYL GROUP IN TETRAHYDROCANNABINOLS

1975 ◽  
Vol 6 (25) ◽  
pp. no-no
Author(s):  
D. B. ULISS ◽  
H. C. DALZELL ◽  
G. R. HANDRICK ◽  
J. F. HOWES ◽  
R. K. RAZDAN
Keyword(s):  
Phenolic Hydroxyl ◽  
Hydroxyl Group

In Vitro Effects of Estrogens on the Δ4-Reduction of Testosterone by Rat Prostate and Liver Preparations

1973 ◽  
Vol 51 (6) ◽  
pp. 735-740 ◽  
Author(s):  
D. K. H. Lee ◽  
J. C. Young ◽  
Y. Tamura ◽  
D. C. Patterson ◽  
C. E. Bird ◽  
...  
Keyword(s):  
Phenolic Hydroxyl ◽  
Hydroxyl Group ◽  
Inhibitory Effects ◽  
Steroid Nucleus ◽  
In Vitro Effects ◽  
Rat Prostate ◽  
Steroid Structure ◽  
Soluble Fractions

The inhibitory effects of six estrogens (estradiol, estriol, ethynylestradiol, mestranol, diethylstilbestrol, and chlorotrianisene) on testosterone Δ4-reduction were studied in rat prostate and liver preparations. In the prostate homogenates only those estrogens with a complete steroid structure and a free phenolic hydroxyl group at position 3 of the steroid nucleus inhibited testosterone 5α-reduction when present at 600 times the concentration of testosterone. The inhibition by estradiol was found to be competitive for prostate homogenate, microsomal, and nuclear preparations. In the liver preparations (homogenate, microsomal, and soluble fractions) all six estrogens inhibited significantly when present at the same concentration as testosterone; diethylstilbestrol and ethynylestradiol were the most effective ones.

scholarly journals Chemoselective Methylation of Phenolic Hydroxyl Group Prevents Quinone Methide Formation and Repolymerization During Lignin Depolymerization

2017 ◽  
Vol 5 (5) ◽  
pp. 3913-3919 ◽  
Author(s):  
Kwang Ho Kim ◽  
Tanmoy Dutta ◽  
Eric D. Walter ◽  
Nancy G. Isern ◽  
John R. Cort ◽  
...  
Keyword(s):  
Phenolic Hydroxyl ◽  
Quinone Methide ◽  
Hydroxyl Group ◽  
Lignin Depolymerization

scholarly journals On the Phenolic Hydroxyl Group of Lignosulfonic Acid and the Existence of Carboxyl Group in Lignosulfonic Acid

1956 ◽  
Vol 29 (1) ◽  
pp. 209-210 ◽  
Author(s):  
Hiroshi Mikawa ◽  
Koichiro Sato ◽  
Chizuko Takasaki ◽  
Kiyo Ebisawa
Keyword(s):  
Phenolic Hydroxyl ◽  
Hydroxyl Group ◽  
Carboxyl Group ◽  
Lignosulfonic Acid
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