| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1346379 | Tetrahedron: Asymmetry | 2011 | 8 Pages |
The reduction of the chiral, racemic nitrone MiPNO provides a secondary hydroxylamine. Its O-acylation with O,O’-dibenzoyl-l-tartaric acid anhydride gives two diastereomers, that can be easily separated by selective dissolution in orthogonal solvents. The recovery of the enantiopure nitrone is then carried out in a single step. The process allows the straightforward isolation of (R) and (S)-MiPNO in 57% and 38% yield, respectively, from rac-MiPNO.
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(S)-(+)-2-Isopropyl-2,3-dimethyl-1-oxy-2,3-dihydro-imidazol-4-one [(S)-MiPNO]C8H14N2O2ee > 98%[α]D25=+16.5 (c 2.0, EtOH)Source of chirality: resolutionAbsolute configuration (S)
(2R,3R)-2,3-Bis-benzoyloxy-succinic acid mono-((S)-2-isopropyl-2,3-dimethyl-4-oxo-imidazolidin-1-yl) esterC26H28N2O9[α]D20=-52.0 (c 1.26, CHCl3)Source of chirality: O,O′-dibenzoyl-l-tartaric acidAbsolute configuration: (2R,3R)(S)
(2R,3R)-2,3-Bis-benzoyloxy-succinic acid mono-((R)-2-isopropyl-2,3-dimethyl-4-oxo-imidazolidin-1-yl) esterC26H28N2O9[α]D20=-54.0 (c 1.08, EtOH)Source of chirality: O,O′-dibenzoyl-l-tartaric acidAbsolute configuration: (2R,3R)(R)
