19780-25-7 2-Butenal, 2-ethyl- 2-Ethyl crotonic aldehyde 2-Ethyl-2-butenal 2-Ethylcrotonaldehyde 3-01-00-03001 (Beilstein Handbook Reference) BRN 1738001 CROTONALDEHYDE, 2-ETHYL- EINECS 243-299-5