Acyclic α,α‐disubstituted β‐phosphonyl esters containing chiral alcoholic auxiliaries were efficiently prepared and evaluated for the lithium naphthalenide‐mediated asymmetric reductive alkylation. Among which, the best diastereoselectivity was received from the substrates bearing a (−)‐phenylmenthyl group in leading to alkylated esters with up to 83:17 dr. The diastereoselectivity is proven to be