Total Synthesis of (−)-Senepodine G and (−)-Cermizine C
摘要:
An efficient, stereospecific synthesis of the alkaloids senepodine G (2 and cermizine C (1) has been completed using the BF3 center dot Et2O-promoted stereospecific addition of Me2CuLi to alpha,beta-unsaturated lactam 6 to provide lactam 3 the addition of MeMgBr followed by HCl to convert 3 to senepodine G (2) (six steps, 40% overall yield), and the stereospecific NaBH4 reduction of 2 to give cermizine C (1) (seven steps, 40% overall yield).
Total Synthesis of (−)-Senepodine G and (−)-Cermizine C
摘要:
An efficient, stereospecific synthesis of the alkaloids senepodine G (2 and cermizine C (1) has been completed using the BF3 center dot Et2O-promoted stereospecific addition of Me2CuLi to alpha,beta-unsaturated lactam 6 to provide lactam 3 the addition of MeMgBr followed by HCl to convert 3 to senepodine G (2) (six steps, 40% overall yield), and the stereospecific NaBH4 reduction of 2 to give cermizine C (1) (seven steps, 40% overall yield).
Preparation of Enantiopure Substituted Piperidines Containing 2-Alkene or 2-Alkyne Chains: Application to Total Syntheses of Natural Quinolizidine-Alkaloids
作者:Guolin Cheng、Xinyan Wang、Deyong Su、Hui Liu、Fei Liu、Yuefei Hu
DOI:10.1021/jo902615u
日期:2010.3.19
nonracemic Betti base as a chiral auxiliary. The key step is that the auxiliary residue was removed by a novel base-catalyzed N-debenzylation via a formation of o-quinone methide mechanism in stead of the traditional hydrogenolysis, by which the alkene or alkyne groups survived. By this method, ten 2-alkene- or 2-alkyne-containing chain substituted piperidines were prepared on the gram scale within
Novel, simple, and convenient strategies for diversely functionalized piperidine derivatives have been developed by using different metal catalyzed reactions starting from enantiopure (R)- and (S)-2-piperidylacetaldehyde. (C) 2011 Elsevier Ltd. All rights reserved.
Enantioselective synthesis of (S)-1,6,7,8,9,9a-hexahydroquinolizin-4-one. Formal synthesis of the lycopodium alkaloids senepodine G and cermizine C
The synthesis of the title compound, a key intermediate in the synthesis of some lycopodium and lupin alkaloids, is reported. From a stereochemical standpoint the key steps are the stereoselective cyclocondensation of ketodiester 1 with (R)-phenylglycinol and the stereocontrolled reduction, with retention of configuration, of the oxazolidine ring in the resulting oxazolopiperidone lactam 2. (C) 2008 Elsevier Ltd. All rights reserved.
Total Synthesis of (−)-Senepodine G and (−)-Cermizine C
作者:Barry B. Snider、James F. Grabowski
DOI:10.1021/jo062067w
日期:2007.2.1
An efficient, stereospecific synthesis of the alkaloids senepodine G (2 and cermizine C (1) has been completed using the BF3 center dot Et2O-promoted stereospecific addition of Me2CuLi to alpha,beta-unsaturated lactam 6 to provide lactam 3 the addition of MeMgBr followed by HCl to convert 3 to senepodine G (2) (six steps, 40% overall yield), and the stereospecific NaBH4 reduction of 2 to give cermizine C (1) (seven steps, 40% overall yield).