1,2,4-Trioxanes bearing a hydrogen substituent at the C-3 position when treated with trithylamine undergo scission of the oxygen-oxygen bond to give the corresponding 1,2-diol monoesters in high yields; similar treatment of a bridged 1,2,4-trioxane afforded the related γ-hydroxy-δ-lactone and its isomeric spirocyclic γ-lactone in 90% yield.