Sulfoxides sulfur-metal exchange

The synthesis of 3 was initiated by reaction of wBuLi with the protected cyclopentenone 2 generating the corresponding vinyllithium reagent by halogen-metal exchange. Subsequent condensation with (S)-(-)-menthyl para-toluenesulfinate (13) provides the enantiodefined sulfoxide substituent in 3.5 Since thermal equilibration of chiral sulfoxides at room temperature is slow, the large sulfur atom is a preferred reaction site in synthetic intermediates to introduce chirality into carbon compounds. 

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