Triphenylphosphine → (2R,4S)-4-fluoro-2-(2-oxo-ethyl)-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester

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Reaction Conditions

Reaction Steps

1 g (3.5 mmol) (2R,4S)-2-allyl-4-fluoro-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester is dissolved in 60 mL dichloromethane/methanol 1:1, cooled to −78° C., flushed with oxygen for two minutes then treated with a flux of ozone until the solution turns light blue. The solution is allowed to warm up to room temperature after addition of 1 g (1.1 eq.) triphenylphosphine, stirred an additional 5 h and column chromatographed (silica gel, TBME/petroleum ether 3:2) to yield 870 mg of the desired product as a clear oil.

Provenance & Evidence