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The divinylcyclopropane-cycloheptadiene rearrangement is an organic chemical transformation that involves the isomerization of a 1,2-divinylcyclopropane into a cycloheptadiene or -triene. It is conceptually related to the Cope rearrangement, but has the advantage of a strong thermodynamic driving force due to the release of ring strain. This thermodynamic power is recently being considered as an alternative energy source.〔Hudlicky, T.; Fan, R.; Reed, J. W.; Gadamasetti, K. G. ''Org. React.'' 1992, ''41'', 1-133. 〕 ==Introduction== In 1960, Vogel discovered that 1,2-divinylcyclopropane rearranges to cycloheptan-1,4-diene.,〔Vogel, E. ''Angew. Chem.'' 1960, ''72'', 4.〕 After his discovery, a series of intense mechanistic investigations of the reaction followed in the 1960s, as researchers realized it bore resemblance (both structural and mechanistic) to the related rearrangement of vinylcyclopropane to cyclopentene. By the 1970s, the rearrangement had achieved synthetic utility〔Wender, P. A.; Eissenstat, M. A.; Filosa, M. P. ''J. Am. Chem. Soc.'' 1979, ''101'', 2196.〕 and to this day it continues to be a useful method for the formation of seven-membered rings. Variations incorporating heteroatoms have been reported (see below). ''(1)'' Advantages: Being a rearrangement, the process exhibits ideal atom economy. It often proceeds spontaneously without the need for a catalyst. Competitive pathways are minimal for the all-carbon rearrangement. Disadvantages: The configuration of the starting materials needs be controlled in many cases—''trans''-divinylcyclopropanes often require heating to facilitate isomerization before rearrangement will occur. Rearrangements involving heteroatoms can exhibit reduced yields due to the formation of side products. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Divinylcyclopropane-cycloheptadiene rearrangement」の詳細全文を読む スポンサード リンク
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