Synthesis of Lactones via C-H Functionalization of Nonactivated C(sp3)-H Bonds.
Johannes RichersMichael HeilmannMarkus DreesKonrad TiefenbacherPublished in: Organic letters (2016)
An electron-deficient amide is utilized as a directing group to functionalize nonactivated C(sp3)-H bonds through radical 1,5-hydrogen abstraction. The γ-bromoamides formed are subsequently converted to γ-lactones under mild conditions. The method described is not limited to tertiary and secondary positions but also allows functionalization of primary nonactivated sp3-hybridized positions in a one-pot sequence. In addition, the broad functional group tolerance renders this method suitable for the late-stage introduction of γ-lactones into complex carbon frameworks.
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