Oxygen Atom Insertion into the Benzylic Carbon-Hydrogen Bond of (R)-(-)-2-Phenylbutane by Methyl(trifluoromethyl)dioxirane: An Efficient and Mild Regio- and Stereoselective Synthesis of (S)-(-)-2-Phenyl-2-butanol

Article abstract of DOI:10.1021/jo00029a030

The efficient conversion of (R)-(-)-2-phenylbutane <(-)-1> into (S)-(-)-2-phenyl-2-butanol <(-)-2> with high configurational retention was achieved under remarkably mild conditions by using methyl(trifluoromethyl)dioxirane (3a).The Arrhenius actication parameters were determined by using methyl(trifluoromethyl)dioxirane (3a) in solution of 1,1,1-trifluoropropanone (TFP) or methylene chloride.A significantly lower activation energy was determined for the oxyfunctionalization of (+/-)-1 by 3a in the less polar methylene chloride.An ordered transition state I is proposed for this regio- and stereoselective O atom insertion into the benzylic C-H bond of hydrocarbon (-)-1.