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.
Protoberberines from Reissert-Compounds VIII [1]. Oxazoloisoquinolines, New and Efficient Educts for the Synthesis of 8-Oxoprotoberberines
作者:Eberhard Reimann、Fritz Grasberger、Kurt Polborn
DOI:10.1007/s00706-003-0013-5
日期:2003.6
Certain benzylated oxazoloisoquinolinones readily available fromReissert compounds provided an efficient access to 8-oxoprotoberberines in three steps. A series of these new precursors as well as several oxoprotoberberines were prepared and the scope and limitation of this procedure were investigated.
Synthese von Dibenzo[a,g]chinolizinen — Ein neuer Zugang zu Protoberberinen
作者:Eberhard Reimann、Helmut Benend
DOI:10.1007/bf00811549
日期:1992.10
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.