Synthesis and Structure of a New Chiral Oxaziridine from (3-Oxo-camphorsulfonyl)imine

Preparation and conformational studies of chiral camphor-derived oxaziridines

“…The exo-3-bromospiro-oxaziridine (7) is difficult to separate from the endo-imine (8), but can be identified by its NMR spectrum, and was used for oxidation without separation. It shows a much higher reactivity towards reducing agents like sulphite, and from oxidations with high concentrations of all reactands and a higher excess of MCPBA, where both imines are oxidized, the endo-3-bromospiro-oxaziridine (13) can be obtained in pure state by destruction of the exo-oxaziridine (7) by several rapid washes of a dichloromethane solution with sodium hydrogen sulphite.…”

“…C,,H17N06S3 requires C, 39.2; H, 4.5; N, 3.8%); v,,, 1650 (GN), 1 350, and 1 130 cm-' (SO,); m/z 303 ( M + -64, 3573, 288 ( M + -79, 25), and 132 (100); and compound (21b) (90%), m.p. 293 "C; (13).-Compound (7). To an efficiently stirred, 2-phase mixture (3: 7) of the bromoimines ( 8) and (9) (2.9 g, 10 mmol) in dichloromethane (100 ml) and sodium carbonate (1.5 g, 15 mmol) in water (50 ml) was added dropwise a solution of 50% MCPBA (4.6 g, 15 mmol) in dichloromethane (100 ml).…”

“…ether (100 ml), a mixture of imine (9) and the oxaziridine (7) (7:3) precipitated out (2.5 g), and could be used directly for oxidations.…”

Synthesis of alkynyl-substituted camphor derivatives and their use in the preparation of paclitaxel-related compounds

“…This versatile intermediate can be reduced to provide a chelating ligand for chiral catalysis [16], or oxidised to oxaziridines used as efficient chiral oxidising reagents [13,17–19]. …”

“…From cheap camphor-10-sulfonic acid ( 1 ), a cyclic sulfonimide 2 can easily be obtained which is readily converted into useful auxiliaries [ 12 ], or oxidized to the oxoimide 3 ( Scheme 1 ) [ 13 – 15 ]. This versatile intermediate can be reduced to provide a chelating ligand for chiral catalysis [ 16 ], or oxidised to oxaziridines used as efficient chiral oxidising reagents [ 13 , 17 – 19 ].…”