Abstract Acid-catalyzed reaction of trifluoromethanesulfonamide with paraformaldehyde in ethyl acetate led to the formation of oxymethylated products that did not form in the reaction carried out in sulfuric acid. Following products were obtained: 5-trifluoromethylsulfonyl-1, 3- dioxazinane, 3, 7-bis-(trifluoromethylsulfonyl)-1, 5, 3, 7-dioxadiazocane, and a complex of trifluoromethanesulfonamide with 2, 4, 8, 10-tetraoxospiro [5, 5] undecene, 1: 1. The ...