SIMULTANEOUS DETERMINATION OF CONFORMATION AND CONFIGURATION USING DISTANCE GEOMETRY
SIMULTANEOUS DETERMINATION OF CONFORMATION AND CONFIGURATION USING DISTANCE GEOMETRY
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DOI：
10.1021/jo00049a062
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发表时间：
1992-11-06
影响因子：
3.6
通讯作者：
REGGELIN, M
中科院分区：
文献类型：
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作者：
MIERKE, DF;REGGELIN, M
我们最近表明，对于一个小的，复杂的氧-唑烷，立体中心的构象和相对构型可以在分子动力学（MD）模拟中使用NOBSY数据的距离限制同时求解。1利用极大的力常数作为NOE约束，文件NOEterm的能量比为维持构型而设置的力场能量分量大很多倍，因此，立体中心可以切换，产生与实验数据一致的立体化学。该过程以研究手性恶唑烷与Diels-Alder不对称反应时合成的标题化合物1,1为例进行了说明。2•nCH，桥头堡位置C8和C9的诱导立体构型以及C6的立体构型是通过上述NOEs和约束MD （rMD）模拟确定的。从（1S, 3S, 6S, 8R, 9R, 1IR, 14S）（exo）结构开始，桥头堡位置的手性迅速逆转，形成内腔结构。1 456年
We have recently shown that for a small, complex oxa-zolidine the conformation and relative configuration of the stereogenic centers could be solved simultaneously with the use of distance restraints from NOBSY data in mo-lecular dynamics (MD) simulations. 1 With the use of an extremely large force constant for the NOE constraints, the energy of file NOEterm is many times larger than the energetic component of the force field set to maintain the configuration, and therefore, the stereogenic centers can switch producing the stereochemistry consistant with the experimental data. This procedure was illustrated with the title compound l, 1 which has been synthesized in the course of examining asymmetric Diels-Alder reactions with chiral oxazolidines. 2• nCH, The induced stereo configuration at the bridgehead positions C8 and C9 as well as the stereo configuration at C6 was determined from NOEs and restrained MD (rMD) simulations as described above. Starting with the (1S, 3S, 6S, 8R, 9R, 1IR, 14S)(exo) structure, the chirality at the bridgehead positions quickly reversed, forming the endo structure. 1 456In