The changes of heterocyclic compounds in Zhenjiang aromatic vinegar during ageing was written by Sun, Zongbao;Yin, Junling;Zhao, Jiewen;Huang, Xingyi;Zou, Xiaobo;Chen, Quansheng;Lin, Hao. And the article was included in Zhongguo Shipin Xuebao in 2015.COA of Formula: C6H9NO This article mentions the following:
The changes of heterocyclic compounds in Zhenjiang aromatic vinegar during ageing were studied by solid-phase microextraction (SPME) and gas chromatog. and mass spectrometry (GC-MS). The result showed that twenty-seven heterocyclic compounds were detected in six kinds of aging time, mainly composed of pyrazine, oxazole, furan and pyrrole. In addition to Zhenjiang aromatic vinegar aged 78 mo, the content of furfural is the highest among the heterocyclic compounds in the other 5 kinds of aging time of Zhenjiang aromatic vinegar. With the increase of aging time, the content of furfural decreased, but most other heterocyclic compounds increased, especially tetra-Me pyrazine, tri-Me pyrazine, 2,6-diethyl-pyrazine, and tri-Me oxazole, whose content was the highest in Zhenjiang aromatic vinegar among the pyrazine and oxazole compounds With the increase of aging time, the content of tetra-Me pyrazine, tri-Me pyrazine, 2,6-diethyl-pyrazine, and tri-Me oxazole was influenced extremely significantly and they were an important indicator of the identification of Zhenjiang aromatic vinegar ageing time. Four oxazole compounds, such as 2-ethyl-4,5-dimethyl oxazole, were discovered in Zhenjiang aromatic vinegar firstly. Heterocyclic compounds, which were rich and high content in the Zhenjiang aromatic vinegar, were an important factor in the formation of the unique flavor of Zhenjiang aromatic vinegar, especially in a longer ageing time. In the experiment, the researchers used many compounds, for example, 2,4,5-Trimethyloxazole (cas: 20662-84-4COA of Formula: C6H9NO).
2,4,5-Trimethyloxazole (cas: 20662-84-4) belongs to oxazolidine derivatives. A common way to produce multisubstituted oxazolidines is by means of cycloaddition reactions. Oxazolidines are cyclic condensation products of β-amino alcohols and aldehydes or ketone, and they undergo a facile and complete hydrolysis in aqueous solution. Alterations in carbonyl moiety control the rate of formation of a given β-amino alcohol.COA of Formula: C6H9NO
Referemce:
Oxazolidine – Wikipedia,
Oxazolidine | C3H7NO – PubChem