<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The first catalytic asymmetric 1, 6‐C—H insertion reaction of α‐diazo esters catalyzed by 1 mol % of a chiral Rh‐complex is developed which provides facile access to optically active oxygen‐containing six‐membered cyclic core structures of biologically active natural products and pharmaceutical agents.</p> </abstract>