The rotational spectrum of a C4 anhydrosugar, 1,4-anhydrothreitol

The rotational spectrum of 1,4-anhydrothreitol (a C4 anhydrosugar) has been assigned by free jet millimeter wave spectroscopy. The structure, characterized by a distorted ring and one O–H⋯O hydrogen bond involving an alcoholic group and the ring oxygen, corresponds to the B3LYP/6-31G∗∗ global conformational minimum. Since C2 sugars have already been observed, and C3 sugars have been extensively searched in the interstellar medium (with controversial results) we propose 1,4-anhydrothreitol to be of interest for astrochemical observation.