
%0 Journal Article
%A Shannon, JS 
%T Studies in Mass Spectrometry. VII. Triterpenoids: Ifflaionic Acid
%J Australian Journal of Chemistry
%D 1963/08/01
%V 16
%N 4
%P 683-689
%K 
%R https://doi.org/10.1071/CH9630683
%U https://www.publish.csiro.au/paper/CH9630683 
%X The mass spectra of the methyl ester of the new unsaturated pentacyclic triterpenoid ifflaionic acid (urs-12-en-3-on-30-oic acid) and some of its chemical derivatives are presented. These may be used to assign position C-20 to the carbomethoxy and C-3 or C-7 to the keto group. Mechanistic proposals for, and the effect of functional groups on, the main fragmentation of the molecular ions (cleavage through ring C) are discussed. 
