A catalytic diastereoselective Prins reaction for hydroxymethylation and hydroxylation of 1,3-diarylpropene was successfully utilized to prepare various 1,3-dioxanes 7 in 14–88% yields. Take advantage of the synthetic intermediate 7h, the key B/C rings in brazilin core could be constructed by the sequential of Friedel–Crafts/Ullmann-Ma rather than Ullmann-Ma/Friedel–Crafts reactions.