Features of the mass spectra of lycoctonine bases with 7,8-methylenedioxy groups

Diterpenoid alkaloids

“…The main processes in the spectra of AloCl2) compounds involves two competing processes : the ejection of a formaldehyde molecule at the expense of the 7,8-methylenedioxy group and the ejection of an OR radical from C-6 (Scheme l). 165 The parameters of the metastable defocusing spectra of the fragment ions of 21 lycoctonine alkaloids with 7,s-methylenedioxy groups have been investigated. 166 The main parameter studied was the ratio of the intensities of the peaks of the metastable and parental ions in percentages (magnitude A).…”

Mass spectrometry in structural studies of diterpene alkaloids

“…When the C(6) acetoxy group is replaced by a hydroxyl or a carbonyl group, abstraction of formaldehyde becomes the prevailing process, whereas its replacement by a methoxy goup results in the predominant abstraction of OMe. 9 The mass spectra of Cls-diterpene alkaloids with an acyloxy group at the C(4) atom are characteristic. In these cases, the most intense peak is due to the abstraction of a molecule of the ester-forming acid from the molecular ion.…”