| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1345992 | Tetrahedron: Asymmetry | 2012 | 5 Pages |
Two diastereomeric isoxazolines were synthesized in a stereoselective manner with 6.64–20.36% diastereoisomeric excess. The cycloaddition of N-sugar-maleimide in the presence of MgBr2 afforded isoxazolines with high diasterioselectivities (76–84% de). The 1,3-dipolar cycloaddition reaction was diastereospecific and enantiomerically pure (3R,4S,5S,6S,3aR,6aS)-pyrazolines were obtained from N-sugar-maleimides via 1,3-proton migration.
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(Z)-4-Oxo-4-(((3R,4S,5S,6S)-1,2;3,4-di-O-isopropylidene-tetrahydro-2H-pyran-2-yl)methylamino)but-2-enoic acidC16H23NO8[α]D22=+86 (c 1, CH2Cl2)Source of chirality: chiral precursorAbsolute configuration: 4-(3R,4S,5S,6S)
1-(6′-Deoxy-1′,2′:3′,4′-di-O-isopropylidene-α-d-glucopyranos-6′-yl)-1H-pyrrole-2,5-dioneC16H21NO7[α]D22=+24 (c 1, CH2Cl2)Source of chirality: chiral precursorAbsolute configuration: 4-(3R,4S,5S,6S)
5,5-Dimethyl-3-[(2,2,7,7-tetramethyl-tetrahydro-bis[1,3]dioxolo[4,5-b;4′,5′-d]pyran-5-ylmethyl)-carbamoyl]-4,5-dihydro-1H-pyrazole-4-carboxylic acid isopropyl esterC22H35N3O8[α]D22=+45 (c 1, CH2Cl2)Source of chirality: chiral precursorAbsolute configuration: (3R,4S,5S,6S,3aR,6aS)
5,5-Diphenyl-3-[(2,2,7,7-tetramethyl-tetrahydro-bis[1,3]dioxolo[4,5-b;4′,5′-d]pyran-5-ylmethyl)-carbamoyl]-4,5-dihydro-1H-pyrazole-4-carboxylic acid benzhydryl esterC42H43N3O8[α]D22=+34 (c 1, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (3R,4S,5S,6S,3aR,6aS)
