(Diethylamino)sulfur trifluoride → methyl (2E)-((3R,5S)-3-{[tert-butyl(diphenyl)silyl]oxy}-5-fluoro-4-methylenecyclohexylidene)acetate

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Reaction Steps

The compound of Example 18A (600 mg, 0.23 mmol) was dissolved in 2.4 mL of dichloromethane, and the resultant solution was cooled to −78° C. (Diethylamino)sulfur trifluoride (DAST, 0.6 mL) was added; the mixture was stirred for 30 minutes, and then quenched by addition of saturated aqueous sodium bicarbonate solution. The mixture was warmed to ambient temperature; the organic phase was dried over Na2SO4. The solvents were removed in vacuo; the residue was purified by chromatography on an Analogix IntelliFlash 280™, eluting with a gradient of 5% to 7% ethyl acetate in hexanes, to give the titled compound, plus some mixed fractions.

Provenance & Evidence