𝔖 Bobbio Scriptorium
✦   LIBER   ✦

1H NMR structural analysis of isomeric tetrazole-substituted spirostan steroids: Shielding effects and conformational study

✍ Scribed by Christopher J. L. Silwood; David B. Davies

Publisher
John Wiley and Sons
Year
1991
Tongue
English
Weight
661 KB
Volume
29
Category
Article
ISSN
0749-1581

No coin nor oath required. For personal study only.

✦ Synopsis

The structures of two pairs of tetrazole-substituted spirostan steroids were characterized by the use of one-and twadimensional 'H NMR measurements. The conformation of the seven-membered spirostan ring A of the steroid was determined by analysis of proton spin coupling Constants and confirmed by 1D and 2D NOE experiments showing interactions between the methyl group and ring protons. The conformation of the tetrazole-substituted ring A was found to he the same for the four isomers, allowing them to be differentiated by the analysis of the effect of tetrazole-ring isornerization on the chemical shifts of neighbouring protons.

KEY WORDS Spirostan steroids Tetrazole-substituted 'H NMR Structural and conformational analysis

📜 SIMILAR VOLUMES

Structural and conformational study of s
Structural and conformational study of substituted triazines by 1H and 13C NMR analysis
✍ Michel Amm; Nicole Platzer; Jean Paul Bouchet; Jean Paul Volland 📂 Article 📅 2001 🏛 John Wiley and Sons 🌐 English ⚖ 216 KB 👁 2 views

Two series of 2,4,6-tris(amino)-s-triazines were studied by 1 H and 13 C NMR. 15 N NMR had previously demonstrated hindered rotation of the acyclic amino substituents (NHallyl, NHpropyl) around the Ar -N bonds at room temperature. In the present work, 1 H and 13 C NMR studies showed that rotation is

Studies on the benzoxazine series. Part
Studies on the benzoxazine series. Part 3—Preparation and 13C NMR structural Study of γ Effects of Some N-substituted 3,4-dihydro-2H-1,3-benzoxazines
✍ Kari Neuvonen; Kalevi Pihlaja 📂 Article 📅 1990 🏛 John Wiley and Sons 🌐 English ⚖ 623 KB

## Abstract Seventeen __N__‐substituted 3,4‐dihydro‐2__H__‐1,3‐benzoxazines [__N__‐substituent = Et, Pr^__i__^, Bu^__t__^, CH~2~C~6~H~5~ or CH(CH~3~)C~6~H~5~] were prepared and their structures studied in the light of ^13^C chemical shifts. The γ effects caused by C(α)‐methyl or C(α)‐phenyl substit

Structural studies on aryl-substituted e
Structural studies on aryl-substituted enaminoketones and their thio analogues. Part I. Analysis of high-resolution 1H, 13C NMR and 13C CP MAS spectra combined with GIAO-DFT calculations
✍ Marta Bugaj; Piotr A. Baran; Piotr Bernatowicz; Patrycja Brożek; Krystyna Kamień 📂 Article 📅 2009 🏛 John Wiley and Sons 🌐 English ⚖ 613 KB

## Abstract A series of aryl‐substituted enaminoketones and their thio analogues in CDCl~3~ solution and in the solid state were studied by the use of high‐resolution ^1^H and ^13^C as well as ^13^C cross polarization magic angle spinning (CP MAS) NMR spectra in combination with gauge including ato