Abstract A convenient synthesis of 4-oxofluorenes starting from 1-oxo-2-indan-butyric acid (1 a) is described. Esterification of 1 a, subsequent reduction of the oxo group and elimination of the resulting hydroxy group lead to ethyl 2-inden-butyrate (3 a), which is subjected to intramolecular ring closure using NaH as condensating agent. Nitration and hydrogenation products of the resulting 1, 2, 3, 9-tetrahydro-4-fluorenone (4 a) are described.
