Non-Catalyzed Thermal Reactions of Acylquinones with Allylstannanes
作者:Kazuhiro Maruyama、Yoshihiro Matano
DOI:10.1246/bcsj.62.3877
日期:1989.12
Thermal reactions of acylquinones with allylstannanes in benzene afforded several kinds of product after column chromatography on silica gel; acyl allyl quinones, acyl allyl epoxy quinones, cyclopentanoid compounds including stannyl moiety, allyl hydroxy quinones, acyl hydroquinones, and acyl allyl hydroquinones. The main product comprises cyclopentanoid compounds, which are novel [2+3] cyclo adducts with 1,2-migration of trialkylstannyl moiety. Spectroscopic examinations (1H NMR and Vis-UV) enabled us to confirm the reaction pathways that four types of precursors were initially generated via polarized tight pair and inverted to isolated products during purification by column chromatography. Similar reactions in acetonitrile showed a remarkable difference in the reactivity, that is, acyl allyl quinones and the corresponding hydroquinones are obtained, but the [2+3] cyclo adducts are not produced at all. From 1H NMR examination, it was confirmed that three types of precursor are generated via solvent separated ion pairs at the initial stage. The rather strong reactivity of acylquinones towards allylstannanes will be due to electron withdrawing ability of acyl group.