Retron Claisen rearrangement

The retron for the Claisen rearrangement transform (see above) is easily established by the application of a Wittig disconnection at each of the equivalent terminal double bonds of 57... 

From a retrosynthetic point of view, the Meerwein-Eschenmoser-Claisen rearrangement shares the basic Claisen retron, a y,<5-unsaturated carbonyl compound, with other variants of the reaction. More specifically, its retron consists of a two-carbon chain branching off an allyhc stereocenter and terminating in an amide or a functional group derived thereof Such a motif can be readily identified in numerous natural products and other synthetic targets. 

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