This product, 3,6-Dimethyl-1,4-dioxane-2,5-dione (or rac-lactide), is the 50:50 racemic mixture of D- and L-Lactide.
L-lactide is available on the website under the product number "36704".
For more information, please visit https://www.sigmaaldrich.com/US/en/product/aldrich/367044