: Enantiopure 2,6-disubstitutedmorpholines have been synthesized through the ring opening of chiral, nonracemic oxiranes with nitrogen nucleophiles, under solid-liquid phase-transfer catalysis (SL-PTC) conditions. The β-hydroxytosyi amides resulting from the ring opening of a first epoxide with TsNH 2 was used as nucleophile, after protection of the hydroxyl group, in the reaction with a second oxirane
The synthesis of enantiopure 2,6-disubstitutedmorpholines was realized through sequential ring opening of two different optically pure oxiranes by a tosylamide, under solid–liquid phase-transfer catalysis (SL-PTC) conditions, mono-O-sulfonylation of the resulting tosylamido-2,2′-diol, and cyclization to the morpholine. The crucial step, the regioselective formation of the monosulfonate, was controlled