hydroxymethyl 1 4 dioxane used in the above reaction can be prepared by a prins reaction wherein formaldehyde is reacted with p dioxene a known compound whose synthesis is described by moss and paige j eng chem data 12 452 1967 in this reaction acid e g sulfuric acid is added to formaldehyde and p dioxene combined with the mixture the acid catalyst can then be neutralized e g with sodium carbonate and water removed by evaporation to leave the desired product preferably the temperature of the reaction is maintained below 40 u00b0 c the amount of acid catalyst used for given reaction conditions can be optimized by routine tests generally increasing catalyst concentration increases by product formation whereas decreasing the concentration lowers the reaction rate the invention is further illustrated by the following example wherein all parts and percentages are by weight unless otherwise indicated about 129 grams p dioxene is added slowly to a mixture of 2 7 grams sulfuric acid and 130 grams 37 formalin a solution of formaldehyde in water during addition the mixture is maintained below 40 u00b0 c the mixture is stirred for about 14 hours and then neutralized to ph 7 with saturated na 2 co 3 solution the solution is concentrated by evaporation of water and filtered to separate na 2 so 4 about 2 grams of the resulting concentrated 2 hydroxy 3 hydroxy methyl 1 4 dioxane is dissolved in 3 grams water and added to a mixture of 7 5 grams cro 3 22 grams h 2 so 4 and 33 7 grams h 2 o cooled to 0 u00b0 c exothermic oxidation is complete in a few minutes yielding str5 the mixture is extracted with an ethanol benzene mixture to strip.