Synthesis of the Integrastatin Nucleus Using the Ramberg−Bäcklund Reaction
摘要:
The first synthesis of the tetracyclic nucleus of the Integrastatins, natural products that have been shown to selectively inhibit HIV-1 integrase, is reported. Key steps of this synthesis involve a novel cis-selective Ramberg-Backlund reaction and an unusual Lewis acid-promoted cyclization step.
Protoberberine ausReissert-Verbindungen, 2. Mitt.: Eine neue Synthese von 8-Methyldibenzo[a,g]chinolizidinen
作者:Eberhard Reimann、Helmut Renz
DOI:10.1002/ardp.19933260502
日期:——
Reissert‐Verbindungen 16 werden mit dem Benzylbromid 14 zu den Dihydroisochinolinen 5 benzyliert. Durch alkalische Spaltung bilden sich daraus die 1‐Benzylisochinoline 6, die mit Säure spontan zu den desoxygenierten Coralynen 4 cyclisieren. 4a sowie das aus 4b erhaltene Chinoliziniumsalz 18 werden mit NaBH4 zu den 8‐Methyl‐trans‐dibenzochinolizidinen 19 reduziert. Die Sequenz 5 → 6 → 4 → 19 beinhaltet einen
Methods of making 2,6-diaryl piperidine derivatives
申请人:Chen Gang
公开号:US20050154201A1
公开(公告)日:2005-07-14
Methods for preparing 2,6-diaryl piperidine derivatives are described. More particularly, 2,6-diaryl piperidines having formula 1-4 are prepared by cyclocondensation of an aryl or heteroaryl aldehyde with 1,3-acetonedicarboxylic acid.
Synthesis of 6-methyl-8H-dibenzo[a,g]quinolizin-8-imines via Reissert compounds
作者:Eberhard Reimann、Rainer Hertel、Jürgen Krauss
DOI:10.1007/s00706-007-0826-8
日期:2008.6
Alkylation of Reissertcompounds derived from 3-methylisoquinolines with several 2-cyanobenzylbromides followed by hydrolytic cleavage provided the corresponding 1-benzyl-3-methylisoquinolines. Treatment of the latter with methylmagnesiumiodide caused cyclization to the title compounds rather than formation of 2-acetylbenzylisoquinolines.
Unexpected Z-stereoselectivity in the Ramberg–Bäcklund reaction of diarylsulfones leading to cis-stilbenes: the effect of aryl substituents and application in the synthesis of the integrastatin nucleus
作者:Jonathan S. Foot、Gerard M. P. Giblin、A. C. Whitwood、R. J. K. Taylor
DOI:10.1039/b418426b
日期:——
With certain substituent patterns, benzylbenzylsulfone systems have been found to give unexpectedly high Z-stereoselectivity (up to E:Z = 1:16) in the Meyers variant of the Ramberg-Backlundreaction. A range of sulfones, bearing various aryl substituents, were explored to rationalize this unprecedented selectivity for Z-stilbene systems. This high level of double bond stereocontrol has also been
Lewis acid mediated endo-cyclisation of trimethylsilylmethylenecyclopropyl imines—a stereoselective route to indolizidines
作者:Suvi Rajamaki、Jeremy D. Kilburn
DOI:10.1039/b418476a
日期:——
Lewis acid mediated endo-cyclisation of trimethylsilylmethylenecyclopropyl imines provides a stereoselective route to indolizidines via a novel cascade sequence.