Ruzicka large ring synthesis

The Ruzicka large-ring synthesis or Ruzicka reaction or Ruzicka cyclization is an organic reaction in which a dicarboxylic acid is converted to a cyclic ketone at high temperature and a suitable catalyst such as thorium oxide. The reaction is named after Lavoslav Ružička, who invented it in 1926.

The reaction has been applied in the synthesis of Exaltone, a synthetic Muscone.