Replacement by fluonne

The reaction of diethyl tartrate with sulfur tetrafluonde at 25 °C results in replacement of one hydroxyl group, whereas at 100 °C, both hydroxyl groups are replaced by fluonne to form a,a -difluorosuccinate [762] The stereochemical outcome of the fluonnation of tartrate esters is retention of configuration at one of the chiral carbon atoms and inversion of configuration at the second chiral center [163,164, 165] Thus, treatment ofdimethyl(+)-L-tartrate with sulfur tetrafluonde gives dimethyl meso-a,a difluorosuccinate as the final product [163, 164], whereas dimethyl meso tartrate is converted into a racemic mixture of D- and L-a,a -difluorosuccmates [765] (equation 80)... 

Functionalized hydrazine groups can be replaced by fluonne. The first example is the replacement ot tnalkylhydrazine groups in bis(l,2,2-trimethylhydrazmo)meth-ane, a hydrazine acetal, by tnchloroacetyl fluonde to fotm 1,1,2- trimethyl-2-fluoromethylhydrazine in 87% yield [5J]... 

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