质谱法研究角型二氢吡喃香豆素双酯化物酰基连接位置

Study on Acyloxy Positions of Angular Diacyloxydihydro pyranocoumarins by Mass Spectrometry

研究了角型二氢吡喃香豆素双酯化物的ＥＩＭＳ，并结合Ｘ－射线单晶衍射分析，证实Ｃ－３′连接的酰氧基较容易和４′－Ｈ脱去羧酸，生成Ｍ－Ｒ１ＣＯＯＨ的碎片离子。而Ｃ－４′连接的酰氧基不能以羧酸的形式脱去，只能脱去酰氧基，生成Ｍ－Ｒ２ＣＯＯ碎片离子，故当两个酰基的质量数不同时，可实际应用ＥＩＭＳ确定酰基的连接位置。

The EIMS of angular diacyloxydihydropyranocoumarins were studied. By combination with X ray diffraction analysis, it is confirmed that the acyloxy attached to C 3′ easily loses R 1COOH with 4′ H, reducing the fragment ion of M R 1COOH. However, the acyloxy attached to C 4′ can′t lose R 2COOH with 3′ H, only splitting the acyloxy and reducing the fragment ion of M R 2COO. If the mass of the R 1 and R 2 is different, EIMS can be measured to determine the positions attached acyloxy.