4940-17-4

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• 30478-77-4 1-(furan-2-yl)pentan-1-ol 

Relevant academic research and scientific papers

Maltol and homolog preparation method by means of molecular oxygen oxidation

The invention provides a maltol and homolog preparation method by means of molecular oxygen oxidation. The method comprises the following steps of charging, a first-stage oxidation reaction, a second-stage oxidation reaction and hydrolysis. According to the first-stage oxidation reaction, alpha-furyl alcohol is used as a raw material, gas with an oxygen content of 15%-85% is used as an oxidizing agent, a heteroatom molecular sieve and basic resin are used as a composite catalyst in a solvent, and an oxidizing ring opening rearrangement reaction is conducted at the temperature of 50-160 DEG C; according to the second-stage oxidation reaction, the temperature drops to 10-40 DEG C, gas with an oxygen content of 90% or above is pumped in, an epoxidation reaction is conducted, and the temperature of the reaction is kept for 0.5-3 h. According to the method, the production yield reaches 50% or above, and the production yield reaches 67% or above in the condition of optimization; the oxidation reaction conducted by using molecular oxygen has the advantages of energy conservation, low cost and environmental protection, and recycling and application of the catalysts are easier to achieve by means of the composite catalyst made from the heteroatom molecular sieve and the basic resin.

Tobacco Smoke Chemistry. 4. A Mass Spectral Study of Alkyl 3-Hydroxy-4-pyrones

3-Hydroxy-4-pyrone and a series of C-alkylated 3-hydroxy-4-pyrones have been synthesized and their behaviour under electron impact investigated.The fragmentation pathways were elucidated with the aid of accurate mass measurements, metastable ion analysis and deuterium labelling.All compounds examined gave a detectable molecular ion which undergoes a retro Diels-Alder type process accompanied by hydrogen transfer to give characteristic ions, which in many cases allow differentiation of positional isomers.Loss of carbon monoxide is encountered from several ions, but to any substantial extent from the molecular ions only in the cases of 3-hydroxy-4-pyrone and 5-hydroxy-2-methyl-4-pyrone.Instead, the more general fragmentation routes involve extrusion of a hydrogen or an alkyl radical from the molecular ion prior to the elimination of carbon monoxide.When the alkyl substituent in 2-alkyl-3-hydroxy- or 2-alkyl-5-hydroxy-4-pyrone has three or more consecutive carbons the molecular ion loses an alkene fragment by a McLafferty type of reaction.The even mass ions formed by this process constitute the base peak in most spectra of this type.Another rearrangement reaction giving even mass ions after loss of an alkene fragment, occurs when the alkyl substituent in the 2-alkyl-3-hydroxy-4-pyrones is branched at the α-carbon.Moreover, γ-bond cleavage of the alkyl side chain vicinal to the hydroxy group becomes important due to anchimeric assistance by the hydroxy group.

Process for preparing 3-oxy-4H-pyran-4-one derivatives

A process for preparing a 3-oxy-4H-pyran-4-one derivative which comprises the steps of: 1. epoxidizing a 3-oxo-3,6-dihydro-2H-pyran derivative with a peroxide to obtain a 4,5-epoxy-3-oxotetrahydropyran derivative, and 2. heating the 4,5-epoxy-3-oxotetrahydropyran derivative.