1,1-Diphenylbutane-1,3-diol: the First Structurally Characterized Example of an Intramolecularly Hydrogen-Bonded Open-Chain 1,3-diol

The crystal structure of the asymmetric 1,3-diol 1,1-diphenylbutane-1,3-diol has been determined and refined to a residual R of 0.039 for 795 observed reflections. Crystals are orthorhombic, space group P2(1)2(1)2(1), With four molecules in a cell of dimensions a 9.625(4), b 16.002(3), c 8.834(3) Angstrom. The compound is unique among the known crystallographically characterized open-chain 1,3-diols in having only intramolecular hydrogen bonding involving the hydroxy groups [O---O 2.602(5) Angstrom].