An enantioselective synthesis of (-)-slaframine (1) has been accomplished by an intramolecular azide [2 + 3] dipolar cycloaddition starting from the readily available aldehyde 12.
Enantiospecific Synthesis of (−)-Slaframine and Related Hydroxylated Indolizidines. Utilization of a Nucleophilic Alaninol Synthon Derived from Serine1
摘要:
A general methodology for the synthesis of indolizidine alkaloids delta-coniceine (12), 1-hydroxyindolizidine (20), desacetoxy slaframine (24), slaframine (34), and an analogue (37) has been developed. This convergent approach utilizes the available chirality in proline and serine and is conceptually different from other approaches. A highly stereoselective coupling of the prolinals with a nucleophilic alaninol synthon provides the precursors for the key cyclization. A novel thermolytic annulation of an oxazolidinone is the key step in the formation of the six-membered piperidine ring. Further elaboration provides the target natural products 24, 34, and 37 in good overall yields.
A versatile synthetic route to indolizidines, (+)-7-deoxy-6-epicastanospermine, (−)-7,8-dideoxy-6-epicastanospermine and (−)-N-acetylslaframine
作者:Sung Ho Kang、Joon Seop Kim、Joo-Hack Youn
DOI:10.1016/s0040-4039(98)02051-6
日期:1998.12
(+)-7-Deoxy-6-epicastanospermine 1, (−)-7,8-dideoxy-6-epicastanospermine 2 and (−)-N-acetylslaframine 4 have been synthesized via the stereoselective intramolecular iodocyclization of trichloroacetimidates generated from cis-olefinic allylicalcohols 7 and 15, respectively.
Synthesis of (-)-<i>N</i>-Acetylslaframine by C-1, C-5 Bis-hydroxyalkylation of (<i>S</i>)-2-(<i>N</i>,<i>N</i>-Dibenzylamino)-1,5-pentanediol via Highly Diastereoselective Lithiation of the Dicarbamate
(-)-N-Acetylslaframine, a stable form of the indolizidine alkaloid (-)-slaframine, has been synthesised by a new strategy. Applying highly stereoselective lithiation and substitution reactions, C-2, C-3 and C-8 of the bicyclic skeleton were introduced to an l-glutamic acid derived diol dicarbamate.
Enantiopure <i>N</i>-Acyldihydropyridones as Synthetic Intermediates: Asymmetric Synthesis of (−)-Slaframine
作者:Daniel L. Comins、Alan B. Fulp
DOI:10.1021/ol991083v
日期:1999.12.1
[formula: see text] An asymmetricsynthesis of (-)-slaframine and N-acetylslaframine has been accomplished starting from an enantiopure dihydropyridone building block. The oxygen-carbon bond at C-1 was incorporated with complete stereoselectivity by using an efficient phenylselenocyclocarbamation reaction.
Carretero, Juan C.; Arrayas, Ramón Gömez, Synlett, 1999, # 1, p. 49 - 52
作者:Carretero, Juan C.、Arrayas, Ramón Gömez
DOI:——
日期:——
A novel thermolytic annulation of an oxazolidinone: an enantiospecific synthesis of (-)-slaframine
作者:Mukund P. Sibi、James W. Christensen、Biqin Li、Paul A. Renhowe
DOI:10.1021/jo00042a002
日期:1992.7
Optically pure beta-aminopiperidines can be prepared in high yields through a thermolytic annulation sequence involving ring opening of an oxazolidinone.