1,1-Dimethoxybut-2-ene 2-BUTENE, 1,1-DIMETHOXY- 2-Butenal dimethyl acetal 21962-24-3 3-01-00-02979 (Beilstein Handbook Reference) BRN 1720659 Crotonaldehyde dimethyl acetal Crotonaldehyde, dimethyl acetal (6CI,7CI,8CI) EINECS 244-683-5 Propylene formal