title: Regioselective O-Sulfonylation of N,N-Bis(2-hydroxyalkyl)tosylamides as a Synthetic Key Step to Enantiopure Morpholines.
abstract: The synthesis of enantiopure 2,6-disubstituted morpholines 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 by taking advantage of the different stereo, electronic, and coordination properties of the oxirane-derived side chains in the diol backbone. As an application of this protocol, a new morpholine-3-carboxamide was synthesized starting from threonine.
authors.affiliation: Department of Chemistry, Università degli Studi di Milano , via Golgi 19, I-20133 Milano, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Foschi
authors.affiliation: Department of Chemistry, Università degli Studi di Milano , via Golgi 19, I-20133 Milano, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Albanese
authors.affiliation: Institute of Molecular Science and Technologies , via Golgi 19, I-20133 Milano, Italy.
authors.forename: Ilir
authors.initials: I
authors.lastname: Pecnikaj
authors.affiliation: Department of Chemistry, Università degli Studi di Milano , via Golgi 19, I-20133 Milano, Italy.
authors.forename: Aaron
authors.initials: A
authors.lastname: Tagliabue
authors.affiliation: Department of Chemistry, Università degli Studi di Milano , via Golgi 19, I-20133 Milano, Italy.|Institute of Molecular Science and Technologies , via Golgi 19, I-20133 Milano, Italy.
authors.forename: Michele
authors.identifier: 0000-0003-2992-3100
authors.initials: M
authors.lastname: Penso