On the Stereochemistry of Irones

In view of the demonstration by Janeicke et al. that different Iris varieties produce enantiomeric irones [6], we complement our 1971 paper on the stereochemistry of the irones [3]. ( 1 ) We give what information we have on the origin of the Iris oil used in [3]; ( 2 ) we sow that we and Ruzicka et al. on whose degradation work our determination of the C(2)‐configurations was based hd the same irones in hand; ( 3 ) we summarize independent assignments of the C(2)‐configurations and the relative configurations of the α‐irones. ( 4 ) We also describe the indentification of a trace of the missing trans ‐γ‐irone in our oil, and ( 5 ) revise the preferred conformation of the cis ‐α‐irones in solution.