# What should be the pKa and IUPAC name of this compound?

Note that this is not squaric acid as it has no double bond between the carbons holding the hydroxy groups.

• Too bad. Then it won't be stabilized in the anionic form the same way as squaric acid, and hence would be less acidic. – Ivan Neretin Mar 8 '17 at 14:26
• @IvanNeretin but the alpha protons will still be labile ... in water I would imagine that there are 3 sp2 carbons the oxygens of which share one proton. It would be interesting to see a geometry optimised molecular model. – user1945827 Mar 8 '17 at 14:29
• What I want to know in particular is its pKa, 'cause I want to know whether it will form effervescence of CO2 with NaHCO3. – Aaron John Sabu Mar 8 '17 at 15:15
• I should be able to get you an optimized geometry and I might be able to figure out a pKa. I'm practicing how to use Gaussian anyway so it should be useful to me to try it on a real example. – Tyberius Mar 9 '17 at 22:00
• The preferred IUPAC name for this compound is 3,4-dihydroxycyclobutane-1,2-dione. If you have any detailed questions about this name, you might want to consider asking a separate question (see also our guidelines on how to ask nomenclature questions). – Faded Giant Mar 10 '17 at 18:19

I guess if you change the structure of the molecule to get both the carbonyl grops opp to each other...(by Lobry De Bryn Van akelstein rearrangement) the hydroxyl carbon would be acidic enough to give a ppt with $\ce{NaHCO3}$