Improved Synthesis of Tricyclo (5.2.1.0^4,10) Decane-2,5,8-Trione by a Pauson-Khand Intramolecular Bis-Annulation

Abstract

Abstract The title compound 1 has been synthesized from diol 3a, either directly or after protection of the two hydroxy groups as benzyl ethers, by an intramolecular Pauson-Khand bis-annulation, followed by catalytic hydrogenation and oxidation in overall yields ranging from 15% (free diol) to 35% (dibenzyl ethers).