Ethyl Acetate → Acetoxymethyl (6R,7R)-7-phenylacetamido-3-(tetrahydrofuran-2-yl)ceph-3-em-4-carboxylate

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Reaction Steps

To a solution of (6R,7R)-7-phenylacetamido-3-(tetrahydrofuran-2-yl)ceph-3-em-4-carboxylic acid (0.303g, 0.78mmol) (obtained in Example 12) in N-methylpyrrolidinone (5ml) was added potassium carbonate (0.37g, 2.66mmol). Bromomethyl acetate (0.30g, 1.95mmol) was added dropwise to the mixture over 1h. The mixture was stirred for a further 1h, then ethyl acetate and water were added. The organic phase was washed with water, brine, dried (MgSO4) and evaporated. The residue was purified by chromatography to give the title compound as a mixture of diastereomers (0.198g, 56%); major diastereomer(S); δH (CDCl3) 1.59 (1H, m), 1.95 (2H, m), 2.12 (3H, s), 2.38 (1H, m), 3.28 (1H, d, J 18.9Hz), 3.59 (1H, d), 3.65 (2H, ABq, J 16.4Hz), 3.88 (2H, m), 4.89 (1H, dd, J 9.0, 6.7Hz), 4.93 (1H, d, J 4.9Hz), 5.84 (3H, m), 6.01 (1H, d, 9.1Hz) and 7.34 (5H, m).

Provenance & Evidence