Direct assignment of the relative configuration in 1,3,n-methyl-branched carbon chains by (1)H NMR spectroscopy

Org Lett. 2010 May 21;12(10):2218-21. doi: 10.1021/ol1005399.

Abstract

On the basis of the assignment of methylene proton signals in (1)H NMR and determination of the chemical shift difference (Deltadelta), the relative configuration of 1,3,n-methyl-branched deoxypropionates can be determined directly. Comparison of the chemical shifts in the corresponding syn- and anti-configured compound pairs shows remarkable differences, while the absolute values depend on the presence and nature of adjacent functional groups. The determination of the Deltadelta values provides a reliable assessment of the relative configuration in 1,3,n-methyl-branched polypropionate chains and is even valid for macrocycles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Magnetic Resonance Spectroscopy / standards
  • Molecular Conformation
  • Polymers / chemistry*
  • Propionates / chemistry*
  • Protons
  • Reference Standards
  • Stereoisomerism

Substances

  • Polymers
  • Propionates
  • Protons