Rearrangements of allene oxide, oxyallyl, and cyclopropanone
Rearrangements of allene oxide, oxyallyl, and cyclopropanone
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DOI：
10.1021/ja9821652
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发表时间：
1998-12-02
影响因子：
15
通讯作者：
Fabian, J
中科院分区：
文献类型：
--
作者：
Hess, BA;Eckart, U;Fabian, J
对丙二烯氧化物重排生成环丙酮、取代环丙酮的外消旋化和取代环丙酮的异构化反应进行了详细的理论研究。发现丙二烯氧化物到环丙酮的重排以逐步的方式进行，其中丙二烯氧化物首先通过新发现的过渡结构转化为氧烯丙基，随后氧烯丙基环丙酮闭环。结果表明，一个先前发现的过渡结构是在手性取代的环丙酮的外消旋化的结果的途径。一个新的过渡结构也被定位，占以前观察到的转化顺式-2，3-二叔丁基环丙酮，其反式非对映异构体。讨论是基于DFT和CASSCF方法的结果。对所有过渡结构进行IRC计算。采用CASPT 2N、QCISD（T）和UQCISD（T）方法计算单点能量。计算结果与实验结果吻合较好。
A detailed theoretical study of the rearrangement of allene oxide to cyclopropanone and the racemization of substituted cyclopropanones and the isomerization of substituted cyclopropanones is presented. The rearrangement of allene oxide to cyclopropanone was found to proceed in a stepwise fashion in which allene oxide first undergoes conversion to oxyallyl via a newly found transition structure with subsequent ring closure of the oxyallyl to cyclopropanone. It is shown that a previously found transition structure is on the pathway that results in the racemization of chiral-substituted cyclopropanones. Anew transition structure was also located that accounts for the previously observed conversion of cis-2,3-di-tert-butylcyclopropanone to its trans diastereomer. The discussion is based on the results of DFT and CASSCF methods. IRC calculations were carried out for all transition structures located. Single-point energies were calculated with the CASPT2N, QCISD(T), and UQCISD(T) methods. Good agreement was found between the calculated results and those available from experiment.