Novel rearrangement of a 2-aryl-3-alkyl-3H-indol-3-ol to a 1,4,5,6-tetrahydro-2,6-methano-1-benzazocin-3(2H)-one with implications for the biosynthesis of aspernomine.
[reaction: see text] Nominine (1) and aspernomine (2) are two biologically important indole diterpenoids that arise from a common digeranylindole precursor. The skeletal relationship of these two natural products was not heretofore understood. We have observed a novel rearrangement of 2-(2-bromophenyl)-3-(3-butenyl)-3H-indol-3-ol (5) to 7, which contains the uncommon 1,4,5,6-tetrahydro-2,6-methano-1-benzazocin-3(2H)-one ring system, under acidic conditions. This rearrangement suggests that aspernomine (2) may arise biosynthetically from nominine (1).
Liu
Yahua
Y
Medicinal Chemistry Research and Global Pharmaceutical Science, Pharmacia Corporation, Kalamazoo, Michigan 49001, USA.
McWhorter
William W
WW
Hadden
Chad E
CE
D004224:Diterpenes / Q000138:chemical synthesis* / Q000378:metabolism; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry*; D006576:Heterocyclic Compounds, 4 or More Rings / Q000138:chemical synthesis* / Q000378:metabolism*; D007211:Indoles / Q000138:chemical synthesis* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure
D004224:Diterpenes; D006575:Heterocyclic Compounds, 3-Ring; D006576:Heterocyclic Compounds, 4 or More Rings; D007211:Indoles; C473424:aspernomine; C473425:nominine