Aspects of mass spectra of organic compounds. Part IV. Cyclopentane monoterpenes of the iridoid group

Abstract

The mass spectra of a number of iridoids (III)–(X) have been examined and general fragmentation mechanisms are discussed which would aid the elucidation of the structures of new members of this class of terpenes. The glycosides themselves could be investigated without further chemical work as the aglycones were formed in the mass spectrometer by cleavage and hydrogen transfer. Deuterium labelling and low energy spectra have been used to confirm some of the many fragmentation processes.