68039-48-5Relevant articles and documents
Method for preparing ligustral
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Paragraph 0008; 0028; 0032; 0038; 0041; 0045; 0047, (2017/08/29)
The invention provides a method for preparing ligustral. The method comprises the following steps: preparing 2,4,4,6-tetramethyl-1,3-dioxane, preparing 2-methyl-1,3-pentadiene, and synthesizing the ligustral. The whole reaction process is gentle in condition, nearly free of side effect, short in time and low in energy consumption, the total yield of the ligustral of the three steps of reaction is greater than 87%; the 2,4,4,6-tetramethyl-1,3-dioxane is prepared in a first step, and the yield is greater than 98%; the 2-methyl-1,3-pentadiene is prepared in a second step, and the yield is greater than 96%; the ligustral is synthesized in a third step, and the yield is greater than 94%; small molecules such as isobutene and acetaldehyde which are low in price and easy to obtain are adopted as raw materials, a process route for preparing the 2-methyl-1,3-pentadiene is innovated, steps such as condensation and dehydration which are high in cost and low in yield in a conventional process are avoided, and the cost of the method is reduced by about 40% when being compared with that of a conventional process.
Photocatalytic degradation of water taste and odour compounds in the presence of polyoxometalates and TiO2: Intermediates and degradation pathways
Fotiou, Theodora,Triantis, Theodoros M.,Kaloudis, Triantafyllos,Papaconstantinou, Elias,Hiskia, Anastasia
, p. 1 - 9 (2014/05/20)
Geosmin (GSM) and 2-methylisoborneol (MIB) are produced by several species of cyanobacteria and actinomycetes. These compounds can taint water and fish causing undesirable taste and odours. Studies have shown that GSM/MIB are resistant in standard water treatments. Polyoxometalates (POM) are efficient photocatalysts in the degradation and mineralization of a great variety of organic pollutants, presenting similar behaviour with the widely published titanium dioxide (TiO2). Photocatalytic degradation of GSM and MIB under UV-A light in the presence of a characteristic POM photocatalyst, SiW 12O404-, in aqueous solution has been studied and compared with the photodegradation by TiO2 suspensions. GSM and MIB are effectively degraded in the presence of both photocatalysts. Addition of OH radical scavengers (KBr and tertiary butyl alcohol, TBA) retards the photodegradation rates of both compounds, suggesting that photodegradation mechanism takes place via OH radicals. Intermediates identified using GC-MS in the case of GSM and MIB, are mainly identical in the presence of both photocatalysts, also suggesting a common reaction mechanism. Possible photocatalytic degradation pathway for both GSM and MIB is proposed.