m-Chloroperbenzoic acid → (4-methoxyphenyl)methyl (5S,6R,7R)-7-[[(2Z)-2-(2-amino-1,3-thiazol-4-yl)-2-methoxyiminoacetyl]amino]-5,8-dioxo-3-[(2S)-oxolan-2-yl]-5lambda4-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate

Participants

Reaction Steps

4-Methoxybenzyl (6R,7R)-7-[2-(2-aminothiazol-4-yl)-2-(Z)-methoxyiminoacetamido]-3-[(S)-tetrahydrofuran-2-yl]ceph-3-em-4-carboxylate (see example 7) (250 mg, 0.44 mmol) in ethyl acetate (25 ml) was stirred in an ice bath and a solution of m-chloroperbenzoic acid (75 mg, 0.44 mmol) in ethyl acetate (5 ml) was added. After 10 min the reaction mixture was washed with dilute aqueous sodium hydrogen carbonate then water followed by drying (magnesium sulphate) and evaporation under reduced pressure. The residue was chromatographed on silica gel eluting with acetone/ethyl acetate mixtures to give the title compound as a white solid (179 mg, 69%); νmax (CHCl3) 1800, 1730, 1680 and 1610 cm-1 ; δH (CDCl3) 1.48-1.64 (1H,m), 1.89-2.00 (2H,m), 2.33-2.47 (1H,m), 3.29 and 3.75 (2H, ABq, J 19 Hz), 3.82 (3H,s), 3.84-3.96 (2H,m), 4.09 (3H,s), 5.06 (1H,dd, J 7, 9 Hz), 5.22 (2H,s), 5.55-5.8 (1H, br s, exch), 6.16 (1H,dd, J 4.5, 10 Hz), 6.91 (2H,d, J 7.9 Hz), 6.98 (1H,s), 7.35 (2H,d, J 9 Hz) and 7.55-7.65 (1H,br, exch). [Mass spectrum: +ve ion (thioglycerol) MH+ (590)].

Provenance & Evidence