Dimethyl Sulfide → [(6R,7S)-2-fluoro-6-methyl-8-oxo-9-(2-oxo-ethyl)-6,7,8,9-tetrahydro-5-oxa-9-aza-benzocyclohepten-7-yl]-carbamic acid tert-butyl ester

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Reaction Steps

A solution of 2.20 g (6.28 mmol) ((6R,7S)-9-allyl-2-fluoro-6-methyl-8-oxo-6,7,8,9-tetrahydro-5-oxa-9-aza-benzocyclohepten-7-yl)-carbamic acid tert-butyl ester in 120 ml dichloromethane was treated with ozone at −75° C. for 20 minutes. Methyl sulfide, 2.27 g (30.6 mmol), was added and the solution was stirred for 4.5 hours at room temperature. The solvent was distilled off under vacuum and the residue was extracted with ethylacetate/water to yield 2.05 g crude [(6R,7S)-2-fluoro-6-methyl-8-oxo-9-(2-oxo-ethyl)-6,7,8,9-tetrahydro-5-oxa-9-aza-benzocyclohepten-7-yl]-carbamic acid tert-butyl ester, MS m/e (%): 353.2 (M+H+, 11), 297.3 (60), 253.2 (100).

Provenance & Evidence