Highly Enantioselective Catalytic Lactonization at Nonactivated Primary and Secondary & gamma;-C-H Bonds

Chiral oxygenated aliphatic moieties are recurrent inbiologicaland pharmaceutically relevant molecules and constitute one of themost versatile types of functionalities for further elaboration. Hereinwe report a protocol for straightforward and general access to chiral & gamma;-lactones via enantioselective oxidation of strongnonactivated primary and secondary C(sp(3) )-H bonds in readily available carboxylic acids. The key enablingaspect is the use of robust sterically encumbered manganese catalyststhat provide outstanding enantioselectivities (up to >99.9%) andyields(up to 96%) employing hydrogen peroxide as the oxidant. The resulting & gamma;-lactones are of immediate interest for the preparationof inter alia natural products and recyclable polymericmaterials.