Related Experiment Video
Updated: Apr 15, 2026

Synthesis and Structure Determination of µ-Conotoxin PIIIA Isomers with Different Disulfide Connectivities
Published on: October 2, 2018
2,14-Dithiacalix[4]arene and its homooxa analogues: synthesis and dynamic NMR study of conformational behaviour
Michal Hucko1, Hana Dvoráková, Václav Eigner
1Department of Organic Chemistry, Institute of Chemical Technology Prague (ICTP), Technicka 5, 166 28, Prague 6, Czech Republic. lhotakp@vscht.cz.
Abstract:
A simple and scalable synthesis of 2,14-dithiacalix[4]arene with alternating bridges (-CH2- and -S-) is reported. Proper selection of the bisphenol-based starting building blocks can provide not only the title compound (58%) but also yet unreported homooxa analogues possessing three different bridging units (-CH2-, -S- and -CH2-O-CH2-) in the molecule. These systems exhibit interesting conformational behaviour allowing for the study of flip-flop motion of the circular hydrogen bond arrays using dynamic NMR techniques.
More Related Videos
Related Concept Videos
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
Stability of Substituted Cyclohexanes
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
Stability of Conjugated Dienes
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.
Chair Conformation of Cyclohexane
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this...
Stereoisomerism of Cyclic Compounds

