The compound is a condensation product.
It is obtained either by treating 3 molecules of acetone with conc. `H_(2)SO_(4)` or passing propyne through a red -hot tube. The product is:

, the compound describes a condensation polymer which can be obtained in two ways, either treating 3 molecules of acetone (CH_(3)COCH_(3)) with conc. H_(2)SO_(4) or passing propyne (CH_(3)-C-=CH) through a red hot tube, the polymer is

Acetone on treating with conc H_(2)SO_(4) gives

The major product obtained in the reaction of oxalic acid with conc, H_(2)SO_(4) upon heating are

the major product obtained in the reaction of oxalic acid with conc, H_(2)SO_(4) upon heating are

Propyne on passing through red hot iron tube gives