Clarification of the stereochemical course of nucleophilic substitution of arylsulfonate-based nucleophile assisting leaving groups.

@article{Braddock2009ClarificationOT,
  title={Clarification of the stereochemical course of nucleophilic substitution of arylsulfonate-based nucleophile assisting leaving groups.},
  author={D. Christopher Braddock and Rebecca H. Pouwer and Jonathan W. Burton and Phillip A Broadwith},
  journal={The Journal of organic chemistry},
  year={2009},
  volume={74 16},
  pages={
          6042-9
        }
}
Secondary alcohols modified as tosylates, PEG-sulfonates, or quisylates undergo inversion of configuration at the reacting center when treated with lithium halide in acetone at reflux, where the PEG-sulfonates and quisylates are substantially more reactive. In sterically hindered cases, elimination is a competing process. In contrast, when treated with TiCl(4), simple secondary sulfonates give chloride products with partial inversion of configuration. Any observed retention of configuration in… 
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