Patent ID: 6239311
Filing Date: 2001-05-29
Classification: C07C,C07D

Abstract:
A process for the preparation of a lactone which comprises:(a) reacting in a reaction mixture the 3,4-dihydroxybutyric acid (HBA) or salt thereof in an aqueous solution of a base selected from the group consisting of an alkali metal hydroxide, an alkaline earth metal hydroxide and mixtures thereof with a strong acid in an amount between about 0.9 and 3 equivalents based upon the base by addition of the acid to the aqueous solution of the base over a period of time at a temperature of less than about 60.degree. C.;(b) mixing a polar organic solvent and an amine containing compound selected from the group consisting of an amine, an ammonium salt and mixtures thereof into the reaction mixture in an amount between about 0.9 and 3 equivalents based upon the base to form an ammonium salt of the HBA in the polar organic solvent; and(c) separating the polar organic solvent containing the ammonium salt of the HBA from the reaction mixture; and(d) heating the ammonium salt of the HBA in the polar organic solvent of the HBA to form the lactone.