Benzo[cd]azulene skeleton: azulene, heptafulvene, and tropone derivatives.
Due to our interest in protein kinase modulating compounds, we developed syntheses for benzo[cd]azulenes. By using very common catalysts and reagents, such as t-BuOK, HCl, and mCPBA, the commercially available guaiazulene is converted in three steps into tricyclic tropone derivatives. Electrophilic aromatic substitution reactions of guaiazulene proceed without a catalyst. Complex one-pot reactions convert 1'-hydroxyalkyl azulenes into tricyclic heptafulvenes, and finally, the mild oxidant mCPBA cleaves the semicyclic C horizontal lineC double bonds to furnish tropones.
Aumüller
Ingo B
IB
Division of Pharmaceutical Chemistry, Faculty of Pharmacy, P.O. Box 56 (Viikinkaari 5 E), FI-00014 University of Helsinki, Finland.
Yli-Kauhaluoma
Jari
J
D052176:Azulenes / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D015394:Molecular Structure; D012717:Sesquiterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D045789:Sesquiterpenes, Guaiane; D013237:Stereoisomerism; D014334:Tropolone / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry
D052176:Azulenes; D012717:Sesquiterpenes; D045789:Sesquiterpenes, Guaiane; C004451:guaiazulene; D014334:Tropolone; C005525:azulene; C003730:tropone