MASS SPECTROMETRY IN STRUCTURAL AND STEREOCHEMICAL PROBLEMS .32. PENTACYCLIC TRITERPENES
MASS SPECTROMETRY IN STRUCTURAL AND STEREOCHEMICAL PROBLEMS .32. PENTACYCLIC TRITERPENES
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DOI：
10.1021/ja00905a036
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发表时间：
1963-01-01
影响因子：
15
通讯作者：
DJERASSI, C
中科院分区：
文献类型：
--
作者：
BUDZIKIEWICZ, H;WILSON, JM;DJERASSI, C
测量α-和β-香树脂醇基团的饱和和不饱和成员以及蒲公英萜醇、鲍厄烯、无水橄榄烷和羽扇烷系列的代表的质谱。已经对主要碎片进行了研究，在大多数情况下，提出了合理的机制来合理化这些离子的形成。在一般情况下，核双键的存在下控制的碎裂行为，和特性的质谱特征已经注意到，这经常允许分配的成员在一个主要类别的一个给定的三萜通过这个标准。此外，官能团的位置通常可以通过考虑片段化模式来缩小。因此，质谱法在三萜领域是一种非常有用的物理方法，当与衍生酮的旋光色散测量相结合时，可以用最少量的材料进行结构解析。
Mass spectra were measured of saturated and unsaturated members of the a- and/3-amyrin group as well as of representatives of the taraxerol, bauerene, friedelane, and lupane series.-Assignments have been made to the principal fragments and, in most instances, plausible mechanisms are proposed to rationalize the formation of these ions. In general, the presence of a nuclear double bond controls the fragmentation behavior, and characteristic mass spectral features have been noted which frequently allow assignment of membership of a given triterpene in one of the major classes by this criterion. In addition, the location of functional groups can often be narrowed down by consideration of the fragmentation pattern. Mass spectrometry thus constitutes an extremely useful physical method in the triterpene field and, when combined with rotatory dispersion meas-urements of derived ketones, can lead to structure elucidation with a minimum quantity of material.