1-BUTEN-3-YNE, 2-METHYL- 2-Methyl-1-buten-3-yne 2-Methylbut-1-en-3-yne 4-01-00-01089 (Beilstein Handbook Reference) 78-80-8 AI3-25132 BRN 0969175 EINECS 201-144-9 Isopropenylacetylene NSC 9296 Valylene