Synthese von Dibenzo[a,g]chinolizinen — Ein neuer Zugang zu Protoberberinen
摘要:
A novel synthesis to prepare dibenzo-8-quinolizinones 8 is reported using the intramolecular cyclisation of the benzylated Reissert compounds 6 for the key step. Methylation of 8 by methyllithium gives partial deoxygenated coralynes 10 which in turn can be reduced by NaBH4 yielding the 8-methyltetrahydro-protoberberines 11. The structures are assigned by NMR-spectroscopy.
Synthese von Dibenzo[a,g]chinolizinen — Ein neuer Zugang zu Protoberberinen
摘要:
A novel synthesis to prepare dibenzo-8-quinolizinones 8 is reported using the intramolecular cyclisation of the benzylated Reissert compounds 6 for the key step. Methylation of 8 by methyllithium gives partial deoxygenated coralynes 10 which in turn can be reduced by NaBH4 yielding the 8-methyltetrahydro-protoberberines 11. The structures are assigned by NMR-spectroscopy.