10.1039/d0ra03420g
The research focuses on the efficient production of bio-based aromatics, specifically vanillin, through the aerobic oxidation of native soft wood lignin. The experiments utilized an aqueous solution of tetrabutylammonium hydroxide (Bu4NOH) to oxidize Japanese cedar wood flour at 120°C for 4 hours under oxygen, yielding vanillin at 23.2 wt% based on the Klason lignin content. This yield is comparable to the alkaline nitrobenzene oxidation method, a benchmark for lignin oxidation processes. The study suggests that vanillin formation primarily occurs through successive reactions: alkaline-catalyzed degradation of lignin's β-ether linkages to form a glycerol end group, oxidation of this end group by O2 to an aldehyde group, and subsequent release of vanillin. The research also indicates that Bu4NOH's performance in vanillin production is superior to simple alkalis like NaOH, due to Bu4NOH being a stronger base and the cation Bu4N+ suppressing the disproportionation of vanillin precursors. The analyses involved high-performance liquid chromatography (HPLC) and gas chromatography/mass spectrometry (GC/MS) to quantify the yields of vanillin, vanillic acid, and other products.
10.1134/S1070363209050144
The study focuses on the synthesis and properties of substituted benzaldehyde phenylhydrazones, which contain hydroxy, alkoxy, and acyloxy groups. These phenylhydrazones were synthesized from aromatic aldehydes of the vanillin series by reacting them with phenylhydrazine. The purpose of these compounds is their potential use in the preparation of nanofilms and nanomaterials, as well as their high light sensitivity, which could be utilized for thermal vacuum spraying of nanofilms for the formation of submicron structures using laser ablation lithography methods. The chemicals used in the study include substituted aromatic aldehydes (vanillin series), phenylhydrazine, and various esters and derivatives of vanillin, which serve as reactants in the synthesis process. The study also involved the use of anhydrous diethyl ether as a solvent and argon atmosphere for the reaction conditions.
10.1248/cpb.31.436
The research focused on the isolation and identification of biologically active compounds from the wood of Abies sachalinensis, a species of fir tree. The purpose of the study was to identify plant constituents that exhibit insect juvenile hormone activity, specifically focusing on (+)-juvabione and its analogs. The researchers successfully isolated (+)-juvabione and two new analogs, along with trans-4-hydroxyeinnamic acid and vanillin. The structures of the new analogs were established using chemical and spectral evidence. The chemicals used in the process included various solvents for extraction and purification, such as acetone, ether, and benzene, as well as reagents for the synthesis and analysis of the compounds, like diazomethane for methylation, chromium trioxide-pyridine complex for oxidation, and NaBH4 for reduction. The study concluded with the determination of the absolute configurations of the hydroxyl groups in the isolated compounds using Horeau's rule and by comparing the compounds to known juvenile hormone mimics. The findings contribute to the understanding of the chemical ecology of fir trees and may have implications for pest control through the use of natural juvenile hormone mimics.
10.1016/j.tetlet.2010.02.018
The research presents a concise and efficient method for synthesizing ailanthoidol, a neolignan compound with various biological properties, starting from vanillin. The key reaction in this synthesis is the intramolecular Wittig reaction, which facilitates the formation of the benzofuran core of ailanthoidol. The researchers optimized the synthesis process to achieve high yields and selectivity, particularly in the intermolecular Wittig reaction step, by studying the effects of different solvents and temperatures. The overall yield of ailanthoidol was 61%, and the synthesis involved minimal protection steps and utilized readily available reagents. This approach offers a simplified and environmentally friendly alternative to previously reported methods that often involve toxic reagents and more cumbersome procedures.
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