Determination of the 18-α/18-β configuration of pentacyclic triterpenes. A multivariate data-analytical approach

Fluoro-α-amino acids. 1—use of 19F NMR s

Fluoro-α-amino acids. 1—use of 19F NMR spectroscopy for the configurational determination of β-fluoro-α-amino acids through complexation by 18-crown-6 ether

✍ S. Hamman; M. C. Salon; C. Béguin 📂 Article 📅 1982 🏛 John Wiley and Sons 🌐 English ⚖ 522 KB

## Abstract __Erythro__ and __threo__ configurational assignments have been made for 11 β‐fluoro‐α‐amino acids or esters using the effect of complexation of the ammonium group by 18‐crown‐6 ether on the ^19^F NMR parameters. For the __erythro__ configurations, ^3^__J__(HF) increases and a high‐fiel