Reaction of di(bromomagnesio)alkanes with unsymmetrically substituted cyclic anhydrides
作者:Persephone Canonne、Gilles Lemay、Denis Bélanger
DOI:10.1016/s0040-4039(00)93679-7
日期:1980.1
Alkylated γ-spirolactones were prepared in one-step reactions in high yields from butane-1,4-diyl and pentane-1,5 diyldimagnesium dibromides and substituted cyclicanhydrides in tetrahydrofuran. In the light of experimental findings electronic and steric factors influence the regiospecificity of this reaction.
A one-pot method for the preparation of furo[3,4-b]pyridine-5(7H)-ones from commercially available 2-bromopyridine-3-carboxylic acid has been developed. Thus, this acid is treated with two molar amounts of butyllithium to generate lithium 2-lithiopyridine-3-carboxylate, which is then allowed to react with carbonyl compounds to afford, after treatment with hydrochloric acid, the desired furopyridinones in reasonable yields.