2-Cyclopenten-1-one, 2-pentyl- 2-Pentyl-2-cyclopenten-1-one 2-Pentylcyclopent-2-en-1-one 25564-22-1 4-07-00-00195 (Beilstein Handbook Reference) Amyl cyclopentenone BRN 1857975 EINECS 247-104-4