1. Department of Organic Chemistry, The Technical University of Denmark, DK-2800 Lyngby, Denmark
Abstract:
The structures of six hexaoxygenated guaianolides esterified with four non isomeric carboxylic acids have been established by 1H NMR and 13C NMR spectroscopy. The acyl residues have been located by chemical ionisation mass spectrometry. Some of the acyl residues are novel for sesquiterpene lactones. The acyl residues in two additional guaianolides esterified with isomeric acids have been located by partial hydrolysis.