Studies on the Synthesis of Phlegmarine-Type <i>Lycopodium</i> Alkaloids: Enantioselective Synthesis of (−)-Cermizine B, (+)-Serratezomine E, and (+)-Luciduline
作者:Alexandre Pinto、Miriam Piccichè、Rosa Griera、Elies Molins、Joan Bosch、Mercedes Amat
DOI:10.1021/acs.joc.8b00983
日期:2018.8.3
The synthesis of the Lycopodium alkaloids, (−)-cermizine B, (+)-serratezomine E, and (+)-luciduline using phenylglycinol-derived tricyclic lactams as chiral scaffolds, is reported. The requisite lactams are prepared by a cyclocondensation reaction between (R)- or (S)-phenylglycinol and the substituted δ-keto ester 11, easily accessible from (R)-pulegone. The factors governing the stereoselectivity
Access to Enantiopure 5-, 7-, and 5,7-Substituted <i>cis</i>-Decahydroquinolines: Enantioselective Synthesis of (−)-Cermizine B
作者:Alexandre Pinto、Rosa Griera、Elies Molins、Israel Fernández、Joan Bosch、Mercedes Amat
DOI:10.1021/acs.orglett.7b00492
日期:2017.4.7
reactions of (R)- or (S)-phenylglycinol with appropriately substituted cyclohexanone-based δ-keto esters are the key steps of short synthetic routes to enantiopure 5-, 7-, and 5,7-substituted cis-decahydroquinolines. The factors governing the stereoselectivity of the cyclocondensation are discussed. The potential of the methodology is illustrated by a protecting-group-free synthesis of the phlegmarine-type
(R)-或(S)-苯基甘氨醇与适当取代的基于环己酮的δ-酮酯的立体收敛环缩合反应是合成5、7和5,7-取代的顺式-十氢喹啉对映体的短合成路线的关键步骤。讨论了控制环缩合立体选择性的因素。该方法的电位由phlegmarine型的无保护基团的合成图示石松( - ) -生物碱cermizine B.
A gram-scale route to phlegmarine alkaloids: rapid total synthesis of (−)-cermizine B
The synthesis of the Lycopodium alkaloid (-)-cermizine B (1), which establishes its absolute configuration, is achieved by combining asymmetric organocatalysis and an uninterrupted eight-step reaction sequence, followed by a final reduction step. This "pot-economy" strategy provides access to the cis-phlegmarine stereoparent embedded in 1 for the first time, rapidly and on a gram-scale.