Method for preparation of (2-hydroxy-3-oxo-cyclopent-1-enyl)-acetic acid esters

摘要

The invention relates to the method of preparation of compounds of formula I, the precursors of homocitric acid lactone and its salts, by coupling of the compounds of formula II with bromoacetic acid esters of formula III.;

主权项

1. A method for preparation of (2-hydroxyl-3-oxo-cyclopent-1-enyl)-acetic acid esters of formula Iwherein R is an alkyl group, or an alkyl phenyl group, said method comprising the steps of:
a) selecting 3-halogeno-cyclopentane-1,2-diones of formula II as a starting compoundwherein:
X is a halogen atom, and Y is H, or a substituted Si atom with R1, R2, R3-substitutions, where R1, R2 and R3 are all CH3; or R1 and R2 are both CH3, and R3=tBu;
b) in presence of a catalyst, coupling the starting compounds of formula II with Zn-derivatives of bromoacetic acid esters of formula III, wherein R is alkyl or an alkyl phenyl group; and
c) Obtaining (2-hydroxyl-3-oxo-cyclopent-1-enyl)-acetic acid esters of formula I.