A synthetic approach to the pseudopterosins, a family of marine natural products shown to be potent anti-inflammatory and analgesic agents, is described. The key step involves a sequential Freidel-Crafts alkylation-acylation reaction whereby a lactone tethered to an arene is directly transformed into the phenalene skeleton of the pseudopterosins through the action of a Lewis or Brønsted-Lowry acid. The scope and limitations of this procedure have been examined in several model systems. This work has shown that the intramolecular alkylation of arenes by lactones proceeds stereospecifically and that the efficiency of this reaction is dependent upon the substitution present on the arene and the tethering alkyl chain. The use of a kinetically controlled iodolactonisation to control the relative stereochemistry between C-3 and C-4 is also notable. Previous syntheses of the pseudopterosins, including synthetic approaches towards the aglycone, are reviewed in Chapter 1.