2-Ethoxy-4-(4-methyl-1,3-dioxolan-2-yl)phenol 68527-76-4 EINECS 271-281-7 Ethyl vanillin propylene glycol acetal Ethyl vanillin propyleneglycol acetal Phenol, 2-ethoxy-4-(4-methyl-1,3-dioxolan-2-yl)-