Schreiner Peter R, Fokin Andrey A, Reisenauer Hans Peter, Tkachenko Boryslav A, Vass Elemér, Olmstead Marilyn M, Bläser Dieter, Boese Roland, Dahl Jeremy E P, Carlson Robert M K
Institut für Organische Chemie der Justus-Liebig-Universität, Heinrich-Buff-Ring 58, D-35392 Giessen, Germany.
J Am Chem Soc. 2009 Aug 19;131(32):11292-3. doi: 10.1021/ja904527g.
We present a new type of sigma-helical structure based on a diamondoid (nanodiamond) framework, C(2)-symmetric [123]tetramantane, whose (+) and (-) isomers could be enantioseparated by HPLC techniques. Bromination of the enantiopure hydrocarbon led to the isolation of (+)-7-bromo-[123]tetramantane, which could be crystallized and subjected to X-ray structure analysis. Using the anomalous dispersion, we have identified this compound as the P isomer for the hydrocarbon moiety. Experimental and computed optical rotatory dispersion (ORD) and vibrational circular dichroism (VCD) spectra independently and in agreement with the X-ray structure analysis gave M-(-) as the configuration of the second eluted parent hydrocarbon isomer.
我们展示了一种基于类金刚石（纳米金刚石）骨架、具有C(2)对称性的[123]四金刚烷的新型σ-螺旋结构，其(+)和(-)异构体可通过高效液相色谱（HPLC）技术进行对映体分离。对映纯烃进行溴化反应，得到了(+)-7-溴-[123]四金刚烷，该化合物能够结晶并进行X射线结构分析。利用反常色散，我们确定该化合物的烃基部分为P异构体。实验和计算得到的旋光色散（ORD）和振动圆二色性（VCD）光谱相互独立，且与X射线结构分析结果一致，确定第二个洗脱的母体烃异构体的构型为M-(-)。
