Nickel-promoted cyclization/carbonylation in the preparation of .alpha.-methylene-.gamma.lactones. Stereospecific synthesis of (.+-.)-frullanolide
Nickel-promoted cyclization/carbonylation in the preparation of .alpha.-methylene-.gamma.lactones. Stereospecific synthesis of (.+-.)-frullanolide
复制标题
制备α-亚甲基-γ内酯时镍促进的环化/羰基化。
DOI：
10.1021/ja00403a065
复制
发表时间：
1981
影响因子：
15
通讯作者：
S. J. Brickner
中科院分区：
文献类型：
--
作者：
M. Semmelhack;S. J. Brickner
由于母离子 (R^ N4) 具有相当长的寿命（约 10^-10" 5 s，亚稳态窗口区），因此它们不能被电子激发，而只能被振动激发 13 并且与通过激光解吸、二次离子质谱、14 等离子体解吸和这些化合物的场解吸（碰撞诱导解离）获得的活性物质密切相关。尽管季铵阳离子迄今为止已被据信在蒸发之前会分解，我们的结果清楚地表明它们在气相中存在，在电子撞击时被激发到更高的振动状态，然后分解产生碎片离子。我们相信我们的结果是第一个报道的电子撞击诱导季铵盐碎片的例子。
Since the parent ions (R^ N4) have considerably long lifetimes (ca. 10^-10" 5 s, metastable window region) they cannot be electronically excited but onlyvibrationally excited13 and are closelyrelated to active species obtained by laser desorption, secondary ion mass spectrometry, 14 plasma desorption, and field desorption (colli-sion-induced dissociation) of these compounds. Although qua-ternary ammonium cations have hitherto been believed to decompose before evaporation, our results indicate clearlythat they survive in a gas phase, are excited into higher vibrational states upon electron impact, and then decompose to give the fragment ions. We believe our results are the first reported examples of electron-impact-induced fragmentation of quaternary ammonium salts. i* x* 1234 r4n+ Í9)(R4n