One-Pot Reaction of Carboxylic Acids and Ynol Ethers for The Synthesis of β‑Keto Esters

An
one-pot reaction of carboxylic acids and ynol ethers for the
synthesis of β-keto esters has been developed. Under promotion
of Ag2O, various carboxylic acids and ynol ethers could
transform to α-acyloxy enol esters, which undergo a following
DMAP-catalyzed rearrangement to deliver β-keto esters rapidly.
This method provides a direct approach to β-keto esters from
carboxylic acids without any preactivation. The protocol features
mild reaction conditions, broad substrate scope, and the products
could be transformed to an array of compounds.