IVANOV Grignard Reagent

For a review of the synthetic applications of metalation hy Grignard reagents at positions other than at triple bonds, see Blagoev, B. Ivanov, D. Synthesis, 1970, 615. 

The bis-deprotonation of arylacetic acids by Grignard reagents is known and the resulting bis(bromomagnesinm) salts (equation 49) have been nsed for preparing / -hydroxy acids (Ivanov reaction). 

A few years ago, Blagonev and Ivanov described the bis-deprotonation of aryl acetic acids by Grignard reagents. These magnesinm dianions, known as Ivanov reagents, react with aldehydes and ketones. Reaction between dianions of phenylacetic acid and benzaldehyde yields the anti S-hydroxy acid as the major diastereomer anti/syn 69/22) (equation 113). This result is in agreement with the formation of a cyclic chair-like transition state according to the model of Zimmerman-Traxler . 

It should be noted that the reaction of acids such as phenylacetic acid with two equivalents of a Grignard reagent gives Ivanov reagents , ArC=C(OMgX)2 [17].)... 

Ivanov reagent. Reaction product of aryl acetic acids and excess Grignard reagent. The reagent may be used in condensations with carbonyl compounds and other Grignard-type reactions. 

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