Practical Route to a New Class of LTD₄ Receptor Antagonists

A general approach to the synthesis of a new class of LTD 4 antagonists is presented. The key diarylpropane framework was prepared by Claisen−Schmidt condensation and selective reduction of the enone. Depending on the bridge to the 7-chloroquinaldine moiety, alkylation or Heck coupling methodology was developed. The chiral sulfides were introduced by asymmetric reduction of the diarylpropanone intermediates and subsequent inversion of the chiral center.