Vicinal difluondes

In other work Rozen added molecular fluorine to a steroidal ene-one dissolved in ethanol at low temperatures to produce a vicinal difluonde in a cleaner, better yield reaction than previously obtainable [55] Although the reaction was not general, the stereoselectivity was very high, and contrary to addition of other halogens, addition was r>ii, characteristic of an electrophilic addition pathway... 

Diethylaminosulfur trifluoride (DAST) reacts with epoxides to give com plex mixtures in which vicinal difluondes, geminal difluondes, and bis(2-fluoroalkyl) ethers are the main components [16] (equations 16 and 17)... 

NMR signals fordifluoromethylene moieties range from -85 to -111 ppm (excludmg difluorocyclopropyls), with vicinal 7jjp values similar to the primary cases More compbcated sphttmg patterns arise from diastereotopic fluorines when a chiral center IS present in the gemmal difluonde Diastereotopic fluorines may differ m chermcal... 

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