Recoverable chiral sulfoxide: Asymmetric diels-alder reaction using optically active 1-(2-p-tolylsulfinyl)pyrrolyl α,β-unsaturated ketones as a dienophile

Article abstract of DOI:10.1246/cl.1997.145

The Diels-Alder reaction of chiral cinnamoyl-and crotonyl (2-p-tolylsulfinyl)pyrrole with cyclopentadiene in the presence of AlCl3 or Yb(OTf)₃ proceeded smoothly to give the corresponding endo adducts in excellent yield with high diastereoselectivity, ranging from 92 to 99% d.e. The chiral auxiliary, 2-pyrrolesulfoxide was efficiently recovered after alcoholysis of the adduct without loss of optical purity.