Efficient synthesis of 1,3-dioxanes catalyzed by trifluoromethanesulfonic acid using formalin as formaldehyde source

Prins cyclizations of styrene derivatives were smoothly conducted in a water solution of formaldehyde using trifluoromethanesulfonic acid (TfOH) as catalyst. While excellent yield was obtained in the Prins cyclization of styrene in the presence of TfOH, low yields or no reaction were observed when other traditional minimal acids catalysts were used.