Patent ID: 6380401
Filing Date: 2002-04-30
Classification: C07D

Abstract:
A process for preparing a 3-hydroxy lactone-containing product from its corresponding open-ring 3,5-dihydroxy acid comprising the steps of:(i) adding a strong mineral acid to a stirring solution of the 3,5-dihydroxy acid in a water-miscible organic solvent, in an amount sufficient to lactonize the 3,5-dihydroxy acid to form the 3-hydroxy lactone-containing product; (ii) adding an excess of additional strong mineral acid to the stirring reaction mixture in an amount sufficient to cause crystallization of the 3-hydroxy lactone-containing product; (iii) collecting and washing the 3-hydroxy lactone-containing product; and (iv) drying the washed 3-hydroxy lactone-containing product.