Highly stereoselective oxy-Michael additions to alpha,beta-disubstituted nitro olefins: asymmetric synthesis of pseudo-norephedrine derivatives and THP* protected alpha-hydroxy ketones

Org Biomol Chem. 2004 Oct 21;2(20):2932-4. doi: 10.1039/b406804c. Epub 2004 Sep 22.

Abstract

The "naked" anion of (S)-6-methyl delta lactol undergoes efficient oxy-Michael addition to alpha,beta-disubstituted nitro olefins to give the THP* protected Henry products with excellent (95-->98% de) stereocontrol at the beta-position and moderate (up to 3 : 1) stereocontrol at the alpha-position in favour of the syn-diastereoisomer. Nitro group reduction with in situN-Boc protection and THP* removal provides alpha,beta-disubstituted ethanolamine derivatives, while treatment with tetrapropylammonium perruthenate gives THP* protected alpha-hydroxy ketone derivatives in high diasteromeric excess.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkenes / chemistry*
  • Ketones / chemistry*
  • Models, Chemical
  • Models, Molecular
  • Molecular Structure
  • Phenylpropanolamine / chemistry*
  • Stereoisomerism

Substances

  • Alkenes
  • Ketones
  • norpseudoephedrine
  • Phenylpropanolamine