A Stereoselective Approach to Pseudoguaianolides

Abstract
The pseudoguaianolides are a class of naturally occurring hydroazulene lactones.1 Damsin (I), one of the structurally simpler members of the class, is a representative example.2 The more complex members may be considered as more highly oxidized or unsaturated derivatives of Damsin.1 Some of these feature a C-7, C-8-fused γ-butyrolactone.1