Kowalski ester homologation
The Kowalski ester homologation is a chemical reaction for the homologation of esters.
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.
Reaction mechanism
The mechanism is disputed.Enolate formation
Ester is deprotonated at the α-position → enolate anion.
CH₂ insertion
Enolate reacts with dihalomethane → introduces a –CH₂– group.
Rearrangement and stabilization
Under basic conditions → homologated ester forms.