1,2-Butanediol, cyclic carbonate 1,2-Butylene carbonate 1,3-Dioxolan-2-one, 4-ethyl- 126828-12-4 127128-77-2 4-19-00-01571 (Beilstein Handbook Reference) 4-Ethyl-1,3-dioxolan-2-one 4437-85-8 BRN 0108553 Carbonic acid, cyclic ethylethylene ester