135892-94-3Relevant articles and documents
Magnesium Methyl Carbonate-Activated Alkylation of Methyl Ketones with an ω-Halo Nitrile, Esters, and Amides
Hand, Elli S.,Johnson, Stephen C.,Baker, David C.
, p. 1348 - 1355 (2007/10/03)
Terminally substituted, extended-chain derivatives of the 2-dibenzofuranyl methyl ketone 6 and its phenylethyl analogue 12 were readily obtained by converting the ketones to magnesium chelates of their β-carboxylated enolates with magnesium methyl carbonate (MMC, methyl methoxymagnesium carbonate, Stiles's reagent), followed by alkylation in situ with ω-halo compounds, X(CH2)n where X = Br and Y = CO2Me, ON, CONMe2, CON(i-Pr)2, CON(CH2)4, or CON(CH2)5 for n = 1; X = Br or I, and Y = CO2Me for n = 2; and X = Br and Y = CO2Me for n = 3. Dimethykarbamoyl chloride (n = 0) gave products derived from MMC and the solvent, N,N-dimethylformamide. The order of reactivity of the halides was α > β > γ and β-I > β-Br. β-Bromo amides were found to be unsuitable reactants. Lower reaction temperatures favored alkylation over competing elimination of HX from methyl β-halopropionate. No self-condensation products of the ketones were observed; however, bis-alkylation and monomethylation products were formed when reaction times were prolonged. In contrast to the unsubstituted β-keto acid 13, all intermediate α-alkyl β-keto acids decarboxylated during the reaction or the workup.
