Halogenation achiral starting material

Halogenation of the achiral starting material CH3CH2CH2CH3 forms two constitutional isomers by replacement of either a 1 ° or 2° hydrogen. 

High halogenated secondary centers and, via activation, oxygenated secondary centers are requisite intermediates for the preparation of enantiomerically-pure natural products and pharmaceuticals. Several methods have recently been reported for the conversion of achiral or prochiral starting materials into high intermediates. 

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