| abstract |
A method of preparing 4,4- dimethyl-1,3-dioxane comprises the steps of cocodensing isobutylene and formaldehyde in an aqueous medium by contact with an acid catalyst, splitting the condensation products into an organic and an aqueous phases, evaporating the aqueous phase to a bottom residue, mixing said bottom residue with an aqueous solution of formaldehyde, and recycling the resulting mixture to the isobutylene-formaldehyde condensation stage. The acid catalysts used in the method are carboxylic acids or mixtures thereof. |