波谱学杂志

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2-酮基-L-古龙酸结构发生改变的核磁共振研究

安志敏,马二倩,杨秋青*   

  1. 河北师范大学 化学与材料科学学院,分析测试中心,河北 石家庄 050024
  • 收稿日期:2013-10-11 修回日期:2014-07-20 出版日期:2014-09-05 发布日期:2014-09-05
  • 作者简介:安志敏(1988-),女,河北张家口人,硕士研究生,主要从事有机化学及波谱分析研究. *通讯联系人:杨秋青,电话:0311-80786318,E-mail: qiuqingyang@sina.com.
  • 基金资助:

    河北师范大学自然科学基金资助项目(L2011Y09).

Structural Changes of 2-Keto-L-Gulonic Acid Studied by NMR Spectroscopy

AN Zhi-min,MA Er-qian,YANG Qiu-qing*   

  1. College of Chemistry and Material Science, Analysis and Testing Center, Hebei Normal University, Shijiazhuang 050024, China
  • Received:2013-10-11 Revised:2014-07-20 Online:2014-09-05 Published:2014-09-05
  • About author:*Corresponding author:YANG Qiu-qing, Tel: 0311-80786318,E-mail: qiuqingyang@sina.com.
  • Supported by:

    河北师范大学自然科学基金资助项目(L2011Y09).

摘要:

发现并揭示了2-酮基-L-古龙酸在许多种溶剂中发生了结构改变,该物质在室温条件下,无需施加任何外力因素,分子中极易发生分子内成环结构变化:分子中的羰基(-C=O)双键断开变单键,形成了2, 5 位半缩醛五元环衍生物,使分子内出现了O-C-O 基团,其标题化合物的核磁共振碳谱(13C NMR)羰基特征峰的化学位移(约200)变到了96,核磁共振2D HMBC 异核相关谱,充分证明了2-酮基-L-古龙酸发生的分子内环合成衍生物的主要产物是五元环的2, 5 位半缩醛衍生物,而非六元环的2, 6 位半缩醛衍生物.

关键词: 液体核磁共振(liquid NMR), 结构变化, 2D NMR, 2-酮基-L-古龙酸

Abstract:

2-keto-L-gulonic acid (2-KLG) changes its molecular structure in many solvents at room temperature. A five-membered intramolecular ring structure can easily be formed by the 2,5-hemiacetal reaction after the opening of the carbonyl group in 2-KLG (-C=O) to form a O-C-O interlinkage. In this study, we showed that the 13C chemical shift of the carbonyl changed from δ 200 towards high field to about δ 96 after forming the intramolecular ring. Two-dimensional HMBC experiments revealed that 2-keto-L-gulonic acid formed five-membered ring 2,5-hemiacetal derivates in seven solvents, instead of
six-membered 2,6-hemiacetal derivates.

Key words: liquid NMR, structure changes, 2D NMR, 2-keto-L-gulonic acid

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