Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. trans-2,3-Butylene carbonate is an organic compound with formula C5H8O3, or (H3C)2(C2H2)(CO3). It is an ester with a carbonate functional group bonded to both free ends of the trans-2,3-butylene group. It is also an heterocyclic compound with a five-membered ring containing two oxygen atoms, and can be viewed as a derivative of dioxolane, namely trans-4,5-dimethyl-1,3-dioxolan-2-one. The compound is an aprotic polar solvent and has been proposed as an ingredient of the electrolyte of lithium batteries.