Soluble magnesium catalyst for preparation of dihydroxy esters

A catalyst and process for preparation of dihydroxy esters from specified hydroxy aldehydes is disclosed. In one embodiment, a catalyst liquid is provided which comprises from 10 percent to 60 percent magnesium salt of a specified alkanoic acid or acids, and from 90 percent to 40 percent of a particular alkanoic acid or acids, the molar ratio of alkanoic acid to magnesium salt being from about 1.5 to 20.3. The catalyst solution or liquid contacts or is contacted with a specified hydroxy aldehyde under suitable reaction conditions to form the desired dihydroxy ester. In another embodiment, dihydroxy esters are derived from specified hydroxy aldehydes by first forming a magnesium catalyst containing liquid by reacting magnesium or magnesium oxide, under suitable conditions, with a suitable alkanoic acid or acids, the acid or acids being provided in excess in specified molar ratios. The magnesium salt-alkanoic acid liquid produced is then employed as a catalyst liquid to convert the respective hydroxy aldehyde under suitable reaction conditions to form the desired dihydroxy ester.