Bicyclic β-Lactones via Intramolecular NCAL Reactions with Cinchona Alkaloids: Effect of the C9-Substituent on Enantioselectivity and Catalyst Conformation

  • Cortez G
  • Oh S
  • Romo D
  • 11


    Mendeley users who have this article in their library.
  • 78


    Citations of this article.


C9-Acylated cinchona alkaloids promote an intramolecular, nucleophile-catalyzed aldol-lactonization (NCAL) reaction leading to optically active bicyclic β-lactones. A mechanistic scheme is proposed for this catalytic, asymmetric process. Only small variations in enantioselectivity were observed for a variety of esters, a carbamate, and a carbonate at the C9 position of quinidine. A combination of coupling constants (3JH8,H9) and nOe data was used to assign predominant solution conformations for these derivatives. Interestingly, a more rigid quinidine derivative gave a complete reversal in the sense of enantioselection.

Author-supplied keywords

  • 2-oxetanones
  • aldol-lactoniza-
  • as
  • asymmetric nucleophilic catalysis
  • cinchona alkaloids and
  • coupling constants
  • in addition to their
  • nuclear overhauser effect
  • their derivatives have proven
  • therapeutic use
  • tions
  • to be highly useful

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text


  • Guillermo S. Cortez

  • Seong Ho Oh

  • Daniel Romo

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free