The solvent-free reaction of 1,3,5-trioxane or paraldehyde with allyl alcohol under mild conditions afforded diallyloxymethane and 1,1-diallyloxyethane in up to 98% yields. The TsOH-CaCl2 (anhydrous) catalytic system used in the reaction allowed generation of HCl during the process. The use of paraformaldehyde instead of 1,3,5-trioxane increased the yield of diallyloxymethane up to 98%.