Analysis of fructofuranose conformations by molecular mechanics

Energies for various envelope and twist conformers of α‐ and β‐ D ‐fructofuranose (FF) have been calculated with MMP2 (85). Values of low energy are found near   4 3 T conformations, and, secondarily, to ranges near   4 3 T shapes. α‐ D ‐FF has a path through the 0 E form for transitions between forms, as found by other workers for β‐ D ‐ribose, while the slightly preferred transition for β‐ D ‐FF is through the 0 E conformer. The majority of conformations of β‐ D ‐FF that have been determined by single‐crystal diffraction studies are in a fairly deep well, with energy values less than 0.5 kcal / mol above the minimum.