Unexpected Course of the Darzens Reaction of Phenyl Esters of α‐Chlorocarboxylic Acids with Carbonyl Compounds–A Novel One‐Step Synthesis of α‐Chloro‐β‐lactones

Abstract

The use of phenyl esters in lieu of alkyl esters drastically changes the course of the Darzens reaction of α-chlorocarboxylates with carbonyl compounds. Instead of the usual glycidic esters, α-chloro-β-lactones 1 are formed in good yields. These lactones are useful synthetic building blocks. R1 = Me, Et, tBu, Ph, PhCH2CH2; R2 = H, Me, Et; R1/R2 = (CH2)4, (CH2)5.