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3.7.3.1 The Classic [2,3]-Wittig Rearrangement

DOI: 10.1055/sos-SD-203-00213

Zeh, J.; Hiersemann, M.Science of Synthesis: Stereoselective Synthesis, (20113377.

As discussed above, the generation of the reactive intermediate for a typical [2,3]-Wittig rearrangement requires the formation of a (formal) carbanion stabilized by an appropriate π- and/or σ-acceptor to provide a useful pKa window for the required Brønsted base and thereby to ensure chemoselectivity. On the other hand, it appears that an increase in the stabilization of the formal negative charge is detrimental to the ability of the carbanion to undergo the desired rearrangement, thereby making this a finely balanced process.

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