Abstract A short synthesis of some trans??pyrrolidine diols is described starting from (2 R, 3 R, 5 R, 6 R)??5, 6??dimethoxy??5, 6??dimethyl [1, 4] dioxane??2, 3??dicarboxylic acid dimethyl ester 3. The key step was the occurrence of a tandem azide reduction/cyclization sequence on mono??azide intermediate 6 upon catalytic hydrogenation. This method afforded both (3 R, 4 R)??(+)??1??benzyl??3, 4??pyrrolidinediol 9a and (3 R, 4 R)??(+)??1??allyl??3, 4?? ...