LABORATORY OBSERVATION OF THE ROTATIONAL SPECTRUM OF A C4 SUGAR, 1,4-ANHYDROERYTHRITOL

The free jetmillimeter wave spectra of 1,4-anhydroerythritol (a C4 anhydrosugar) and of three deuterated isotopologues have been recorded in the frequency region 59.6-78.3 GHz. Rotational transitions have been assigned only for the lowest in energy conformer (according to DFT calculations). Its structure is characterized by a distorted ring and two O-H center dot center dot center dot O hydrogen bonds involving the two alcoholic groups and the ring oxygen. Since C2 sugars have already been observed, and C3 sugars have been extensively searched, with controversial results, in the interstellar medium, we believe that 1,4-anhydroerythritol, a C4 sugar, to be of interest for astrochemical observation of larger sugar molecules. Accurate rest frequencies are provided for the radio-astronomical search.