Preparation of acrylic acid derivatives from alpha- or beta-hydroxy carboxylic acids

摘要

The invention is directed to a process for the preparation of α,&bgr;-unsaturated acids, esters and amides from α- or &bgr;-hydroxycarboxylic acids or esters or precursors in high yields and high selectivity. The α,&bgr;-unsaturated acids or esters are optionally prepared in the presence of specific dehydration and/or esterification catalysts. The α,&bgr;-unsaturated amides or substituted amides are prepared optionally in the presence of a dehydration and/or amidation catalyst. The source of α- or &bgr;-hydroxycarboxylic acids or precusor is preferably from a renewable resource. The precursor is defined herein.