PRODUCTION OF BETA,GAMMA-UNSATURATED ALPHA-KETO ESTER

摘要

PURPOSE: To obtain the subject compound useful as a synthetic intermediate for pharmaceuticals, agricultural chemicals, etc., from an inexpensive raw material using a simple reaction operation by treating a specific γ-alkoxy-α-keto ester with an acid catalyst or a base catalyst to eliminate an alcohol from the ester. ;CONSTITUTION: The objective β,γ-unsaturated α-keto ester of formula II (e.g. 2-oxo-4-phenyl-3-butenoic acid ethyl ester) is produced by dissolving a γ-alkoxy-α- keto ester of formula I (R¹ is alkyl, aryl, vinyl or heterocyclic compound residue; R² and R³ are lower alkyl) (e.g. 4-methoxy-2-oxo-4-phenylbutanoic acid ethyl ester) in a solvent such as benzene, adding an acid catalyst (e.g. silica gel) or a base catalyst to the solution, reacting for 1hr under heating to eliminate an alcohol, leaving the reaction product to cool, filtering to separate the catalyst and purifying the filtrate by silica gel chromatography.;COPYRIGHT: (C)1993,JPO&Japio