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Scope and mechanism of the rearrangement of alkoxybenzyl anions to alkylphenoxide ions; cyclophanes from 2,6-dimethylanisole.

Alkoxy alkyl groups migrate to benzylic carbon when alkyl alkylphenyl ethers are treated with n-butyllithium and potassium t-butoxide. For alkyl 2,6-dialkylphenyl ethers, yields of the rearrangement products range from 45-70%. Rearrangement products are obtained in 10-30% yield from other dimethylanisoles and methylanisoles. The reactions appear to proceed by homolytic cleavage of the alkoxy alkyl group of alkoxybenzyl anions followed by recombination of the resulting radical pair in a different way. The reaction is useful for preparing 2,6-dialkylphenols and their corresponding ethers. The rearrangement can be avoided by using methyl ethers and working at or below room temperature. This was shown by reacting the dianion from methyl 2,6-dimathylanisole with dialkyl sulfates to give methyl 2,6-dialkylanisoles, with a,ω-dihalides to give methoxy[n]metacyclophanes (n = 8-15), dimethoxy[n.n]metacyclophanes (n = 5-10) and trimethoxy[S.S.S]metacyclophane, and with oxidizing agents to yield dimethoxy[2.2]metacyclophane.

Identiferoai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/184679
Date January 1989
CreatorsSuvannachut, Kessara.
ContributorsBates, Robert B., Steelink, Cornelius, Keller, Philip C., Mulvaney, James E., Rund, John V.
PublisherThe University of Arizona.
Source SetsUniversity of Arizona
LanguageEnglish
Detected LanguageEnglish
Typetext, Dissertation-Reproduction (electronic)
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.

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