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
Synthesis of angularly fused cyclopentanoids and analogous tricycles via photoinduced ketyl radical/radical anion fragmentation–cyclization reactions
作者:Nikolay T. Tzvetkov、Torsten Arndt、Jochen Mattay
DOI:10.1016/j.tet.2007.07.092
日期:2007.10
Angular fused tricycles were synthesized through intramolecular tandem fragmentation–cyclizationreactions by photochemically induced electron transfer (PET) of tricyclic α-cyclopropyl ketones with an unsaturated side chain at the position γ to the carbonyl group. The reactions resulted in regioselective cleavage of a β-cyclopropyl bond with formation of angular fused tricyclic ring systems via ketyl
通过分子内串联断裂-环化反应,通过光化学诱导的电子转移(PET)三环α-环丙基酮在羰基的γ位具有不饱和侧链,合成了稠合的三环角化合物。该反应导致β-环丙基键的区域选择性裂解,并通过酮基自由基/自由基阴离子作为反应性中间体形成有角稠合的三环系统。通常,三乙胺(TEA)在乙腈中用作强还原剂。环化步骤的首选区域选择性(外向与内向)取决于在三环α-环丙基酮的季碳中心(Cβ')处的取代模式。此外,我们还检查了有角二恶英-三喹烷的合成的两步途径,包括烯丙氧基取代的环戊[ c ]呋喃酮衍生物的光解以及随后的二恶唑-[4.5.5.5] fenestrane在还原条件下的β裂解。 PET条件。
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.