A double Mannich approach to the synthesis of substituted piperidones—application to the synthesis of substituted E-ring analogues of methyllycaconitine
作者:Yinman Chan、Jared Balle、J. Kevin Sparrow、Peter D.W. Boyd、Margaret A. Brimble、David Barker
DOI:10.1016/j.tet.2010.06.084
日期:2010.8
The double Mannich reaction of acyclic α,γ-substituted β-keto esters and bis(aminol) ethers gives substituted 3,5-substituted-4-piperidones with high levels of diastereoselectivity. These piperdiones can be easily transformed into substituted E-ring analogues of the delphinium alkaloid methyllycacotine.
Efficient Synthesis of the Azabicyclo[3.3.1]nonane Ring System in the Alkaloid Methyllycaconitine Using Bis(alkoxymethyl)alkylamines as Aminoalkylating Agents in a Double Mannich Reaction
作者:Margaret A. Brimble、Constanze Brocke
DOI:10.1002/ejoc.200500003
日期:2005.6
The doubleMannichreaction of cyclic β-keto esters with bis(alkoxymethyl)alkylamines provides an efficient and versatile method for the construction of azabicyclo[3.3.1]nonanes and azabicyclo[3.2.1]octanes. The optimum conditions for efficientreaction involve use of the activator trichloromethylsilane in acetonitrile as solvent at ambient temperature. The utility of this synthetic method is further
Application of a Double Mannich Reaction Using<i>Bis</i>(aminol) Ethers in the Synthesis of AE Ring Analogues of Methyl Lycaconitine
作者:Margaret A. Brimble、Constanze Brocke、Diana S.-H. Lin、Malcolm D. McLeod
DOI:10.1055/s-2004-831340
日期:——
An efficient method for the construction of azabicyclo[3.3. 1]nonanes and azabicyclo[3.2. 1]octanes is reported via double Mannich reaction of cyclic ketoesters with bis(aminol) ethers. This method is applied to the synthesis of AE ring analogues of methyl lycaconitine.
Reaction of 9-methylene-3-azabicyclo[3.3.1]nonanes with trifluoroperacetic acid results in stereoselective epoxidation to give the syn-epoxide. Intermolecular hydrogen bonding between the protonated tertiary amine and the peracid is responsible for the high levels of stereoselectivity.