3-Methyl-pent-2-en,Gemische von hoehersiedendem und niedrigersiedendem 3-Methyl-penten-(2), 3-Methyl-pentanon-(2)-al-(1), 3-methyl-2-oxo-valeraldehyde, 3-methyl-2-oxo-pentanal, 3-methyl-pent-2-ene, 3-Methyl-penten-(2),Gemische von cis-und trans-Form und Praeparate von ungewisser Konfiguration, 3-methyl-2-pentene, sek.-Butyl-glyoxal, MeCH=C(Me)Et, sec-Butylglyoxal, 3-Methyl-2-oxo-valeraldehyd, Valeraldehyde,a-keto-b-methyl-(1CI), Pentanal,3-methyl-2-oxo, 3-methyl-pentene-(2),mixtures of cis-and trans-form and substances of uncertain configuration