Highly enantio- and diastereoselective Brassard type hetero-Diels-Alder approach to 5-methyl-containing alpha,beta-unsaturated delta-lactones

J Org Chem. 2006 May 26;71(11):4141-6. doi: 10.1021/jo060046w.

Abstract

Two efficient new chiral copper (II) Schiff base complexes were developed for the highly enantio- and diastereoselective HDA reaction of Brassard type diene 1b with aldehydes, to afford the corresponding 5-methyl-containing alpha,beta-unsaturated delta-lactone derivatives in moderate yields, high enantioselectivities (up to 99% ee) and excellent diastereoselectivities (up to 99:1 anti/syn). On the basis of the absolute configuration of 4a-4j disclosed by X-ray diffraction and CD analysis, a possible transition-state model for the enantio- and diastereoselective catalytic reaction has been proposed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Lactones / chemical synthesis*
  • Models, Molecular
  • Molecular Structure

Substances

  • Lactones