The Z conformer of 1,2-ethenediol was detected by Rivilla and coworkers toward the G+0.693–0.027 molecular cloud near the center of the galaxy, as reported in 2022. The observations were made with the Yebes 40m and IRAM 30m telescopes. New spectroscopy of Z-1,2-ethenediol by Melosso and coworkers was used to assign transitions. The detection has evidently not yet been confirmed with additional observations or observed in other sources. Spectral data for deuterated Z-1,2-ethenediol measured by Nonne and coworkers is available.

Z-1,2-ethenediol is the enol form of glycolaldehyde, where a hydrogen atom has transferred to oxygen to form a second –OH group (hence "diol"), and both groups are on the same ("Z"="zusammen") side of the C-C double bond. There is also an E conformer of 1,2-ethenediol ("E"="entgegen").