Intramolecular<i>Wittig</i>Reaction: A New Synthesis of (<i>S</i>)-Pyrrolam A
作者:Mahesh S. Majik、Perunninakulath S. Parameswaran、Santosh G. Tilve
DOI:10.1002/hlca.200890163
日期:2008.8
A straightforward synthesis of (S)-pyrrolam A is described. The synthesis involves in situ generation of the phosphorane 3, followed by an intramolecularWittigreaction to furnish (S)-pyrrolam A.
Enantioselective sp<sup>3</sup> C–H alkylation of γ-butyrolactam by a chiral Ir(<scp>i</scp>) catalyst for the synthesis of 4-substituted γ-amino acids
作者:Yu-ki Tahara、Masamichi Michino、Mamoru Ito、Kyalo Stephen Kanyiva、Takanori Shibata
DOI:10.1039/c5cc07102j
日期:——
Ir-catalyzed sp3 C–H alkylation of γ-butyrolactam with alkenes was used for the highly enantioselective synthesis of 5-substituted γ-lactams, which were readily converted into chiral 4-substituted γ-amino acids.
An efficient synthetic method for the preparation of optically active pyrroloazocine, pyrroloazepine, quinolizidene, indolizidine using ring closing olefin metahesis (RCM) is described.
Short Syntheses of (-)-<b>(</b>
<b><i>R</i></b>
<b>)</b>-Pyrrolam A and (1<b><i>S</i></b>)-1-Hydroxyindolizidin-3-one
作者:Rainer Schobert、André Wicklein
DOI:10.1055/s-2007-966035
日期:——
(-)-( R)-Pyrrolam A was prepared in five steps, 95% ee and 25% yield, from ( R)-benzyl prolinate. Closure of the pyrrolidine ring was effected by a domino addition-Wittig alkenation reaction with ylide Ph 3 PCCO, immobilized on a polystyrene resin. An indolizidinone was obtained likewise from ( R)-benzyl pipecolate. The reduction of 1-ketopyrrolizidinones and 1-ketoindolizidinones is described.
(-)-(R)-Pyrrolam A 由 (R)-脯氨酸苄酯分五步制备,95% ee 和 25% 产率。吡咯烷环的闭合通过与叶立德 Ph 3 PCCO 的多米诺加成-维蒂希烯化反应实现,固定在聚苯乙烯树脂上。同样由(R)-苄基哌可酸得到吲哚齐酮。描述了 1-ketopyrrolizidinones 和 1-ketoindolizidinones 的还原。
An efficient route to the pyrrolizidine ring system via an N-acyl anion cyclisation process
作者:Anthony Murray、George R. Proctor、P.John Murray
DOI:10.1016/0040-4020(96)00049-x
日期:1996.3
An enantioselective route to the pyrrolizidineringsystem has been developed which uses an N-acyl anion cyclisation reaction as the key step. This methodology has provided the natural pyrrolizidines (−)-(1R, 8S)-1-hydroxy-pyrrolizidine 7, (−)-pyrrolizidin-1-ene-3-one 9 and (±)-trachelanthamidine 14. Extension of the process to an N-propionyl substrate provides ready access to a series of 2-methyl