A biosynthetic pathway was recently proposed for the polycyclic, cytotoxic compound aspernomine, isolated from the fungus Aspergillus nomius (J. Am. Chem. Soc. 2012, 134, 8078–8081):
(a) Two of the six-membered rings are represented in chair conformations. Is the connection between these two rings analogous to that in cis- or trans-decalin?