The Kowalski ester homologation is a chemical reaction for the homologation of esters.[1][2]
This reaction was designed as a safer alternative to the Arndt–Eistert synthesis, avoiding the need for diazomethane. The Kowalski reaction is named after its inventor, Conrad J. Kowalski.
The mechanism is disputed.[further explanation needed]
By changing the reagent in the second step of the reaction, the Kowalski ester homologation can also be used for the preparation of silyl ynol ethers.[citation needed]