They are designated as dilactides, trilactides, etc., according to the number of hydroxy acid residues.

The dilactide derived from lactic acid has the formula [CH(CH3)CO2]2.

This lactide has attracted interest because it is derived from abundant renewable resources and is the precursor to a biodegradable plastic.

[3] The dilactide derived from lactic acid can exist in three different stereoisomeric forms.

All three stereoisomers undergo epimerisation in the presence of organic and inorganic bases in solution.