Identification of the furanose ring conformations and the factors driving their adoption

Abstract

Three groups of furanoses with restricted freedom of rotation on the C3–C4, C2–C3, and C1–C2 bonds, respectively, are presented. Conformational analysis of these furanoses is conducted based on the proton nuclear magnetic resonance (1H NMR) spectroscopy, density functional theory (DFT) calculations, and X-ray analysis. It is shown that the particular group of the presented furanoses is locked in the specific conformation. These are the 1T2-like, the 0E-like, and the 3T4-like conformation, respectively. Characteristic 1H NMR spectra of these three conformations are presented and the factors influencing the conformational preferences of the analyzed furanoses are discussed.