Annulations that combine di-acceptors with bis-nucleophiles are uncommon. Here, we report the synthesis of 1,4-dioxanes from 3-aryloxetan-3-ols, as 1,2-bis-electrophiles, and 1,2-diols. Brønsted acid Tf2NH catalyzes both the selec-tive activation of the oxetanol, to form an oxetane carbocation that reacts with the diol, and intramolecular ring-opening of the oxetane. High regio and diastereoselectivity is achieved with unsymmetrical diols. The substituted dioxanes and fused bicyclic products present interesting motifs for drug discovery and can be further functionalized.