𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Conformational analysis 18—lanthanide-induced shift (LIS) investigation of some 2-substituted 1,3-dioxanes

✍ Scribed by Raymond J. Abraham; Kerry Wallace; Suzanne Wilkins; Fernando Sancassan

Publisher
John Wiley and Sons
Year
1992
Tongue
English
Weight
540 KB
Volume
30
Category
Article
ISSN
0749-1581

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

A LIS analysis of 2‐isopropyl‐1,3‐dioxane (1) and 2‐methyl‐2‐phenyl‐1,3‐dioxane (2) is reported. The monodentate complexing model gives good agreement with the observed shifts in both compounds, whereas the bidentate model (lanthanum binding to both oxygens) does not give an acceptable solution. In 1 the lanthanide complexes almost exclusively (90%) with the axial lone pair of the oxygen atom. The four‐site binding model gives excellent agreement with the observed shifts (R~x~ 3.5%). In 2 a similar lanthanide binding is found, and the analysis of the LIS allows both the deduction of the molecular conformation (C‐2‐methyl equatorial, C‐2‐phenyl axial) and also the orientation of the phenyl group (perpendicular).

📜 SIMILAR VOLUMES

Conformational analysis. 15—Lanthanide-i
Conformational analysis. 15—Lanthanide-induced shift investigation of 2-exo-norborneol using tailored models of lanthanide complexation
✍ Raymond J. Abraham; A. E. Rowan 📂 Article 📅 1988 🏛 John Wiley and Sons 🌐 English ⚖ 758 KB

The complete assignment of the proton chemical shifts for kxo-norborneol was obtained from a COSY experiment at 250 MHz. Using these assignments the conformation of this molecule in solution was studied using the lanthanide-induced shift technique, applying a new three-site lanthanide complexation m