Magnesium bromide promoted Barbier-type intramolecular cyclization of halo-substituted acetals, ketals, and orthoesters
作者:Jui-Wen Huang、Chiar-Dy Chen、Man-kit Leung
DOI:10.1016/s0040-4039(99)01813-4
日期:1999.12
Although acetals, ketals and orthoesters are commonly used as protective groups against organometallic reagents, Grignard reagents derived from halo-acetals, ketals, or orthoesters cyclize intramolecularly under MgBr2 promoted conditions, giving rise to the corresponding cycloalkanol and cycloalkanone derivatives. Our results also suggest a Lewis acid catalyzed push-pull mechanism operating for the
尽管缩醛,缩酮和原酸酯通常用作抵抗有机金属试剂的保护基,但是衍生自卤代缩醛,缩酮或原酸酯的格氏试剂在MgBr 2促进的条件下分子内环化,产生了相应的环烷醇和环烷酮衍生物。我们的结果还表明,路易斯酸催化的推挽机制可用于环化反应。