Vinylcyclopropane- cyclopentene rearrangement, metal-catalyzed

The substituent effects have been quantitatively addressed in the context of specific transformations, for example the vinylcyclopropane-cyclopentene rearrangement, and will be discussed in the appropriate sections. The donor/acceptor principles have been applied to thermal, heterolytic and transition metal catalyzed rearrangements and have been reviewed. These principles take into account the possible intermediate structures listed in Table 1 and are used to explain the reactivity of a particular cyclopropane system. In the discussion that follows emphasis will be given to the processes that are uniformly selective with regard to regio-, stereo- and enantio-chemical integrity of the products. 

Metal-promoted vinylcyclopropane C3 - C5 ring expansions have been reported. Thus, ethyl 2-methoxy-2-vinylcyclopropanecarboxylate 393 rearranged to a 2 1 mixture of 3-methoxy-2-cyclopentenecarboxylate 396 and 3-methoxy-3-cyclopentene-carboxylate 397 on heating at 160 °C in the presence of catalytic amounts of copper bronze or copper(I) chloride in contrast, platinum and rhodium complexes catalyzed... 

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