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7.6.13.11 Method 11: Reactions Involving Magnesium 2-Ethoxyethoxide

DOI: 10.1055/sos-SD-007-00630

Shimizu, M.Science of Synthesis, (20047651.

The metalating ability of alkyllithium reagents and their tendency to cleave tetrahydrofuran are greatly diminished in the presence of magnesium 2-ethoxyethoxide (3) (see Section 7.6.13.3). This property can be used advantageously to generate organolithium reagents in tetrahydrofuran in the presence of magnesium 2-ethoxyethoxide under conditions that do not normally favor their stability. Thus, halo compounds can be converted into the corresponding organometallic reagents by treatment with lithium metal in the presence of magnesium 2-ethoxyethoxide in tetrahydrofuran (Scheme 11).[‌8‌] In the absence of magnesium 2-ethoxyethoxide, the alkyllithium reagents that are formed react with the solvent, resulting in reduced yields and, often, alternative products. In the case of the preparation of arylmetal reagents, the presence of magnesium 2-ethoxyethoxide suppresses both subsequent ortho-metalation and Wittig rearrangement to give a clean replacement of halogen by the metal.

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