One-step synthesis of tricyclo[5.3.1.0<sup>3,8</sup>]undecan-4,11-diones by three consecutive Michael reactions. A formal synthesis of (±)-seychellene

“…H) Ethoxycarbonylmethylation at the nitrogen of a thiazole, ylid formation, cycloaddition to the C-C double bond of an enone, and tetrahydrofuran formation are the steps leading from two achiral educts to a tricyclic system with five centers of chirality [383]. I) Three-fold Michael addition produces four stereogenic centers [384]. K) Enarnine acylation, followed by intramolecular Michael and Dieckmann reactions, transforms methacrylyl chloride and a cyclohexanone derivative directly into the adamantane skeleton [385].…”

Section: Transition-metal Derivatives-always Good For a Discoverymentioning

confidence: 99%

Organic Synthesis—Where now?

Seebàch¹

1990

Angew. Chem. Int. Ed. Engl.

565

224

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This review article is an attempt to sketch the important developments in organic synthesis during the past 25 years, and to project them into the future.—The primary motivations that once induced chemists to undertake natural product syntheses no longer exist. Instead of target structures themselves, molecular function and activity now occupy center stage. Thus, inhibitors with an affinity for all the important natural enzymes and receptors have moved to the fore as potential synthetic targets.—New synthetic methods are most likely to be encountered in the fields of biological and organometallic chemistry. Enzymes, whole organisms, and cell cultures for enan‐tioselective synthesis of specific substances have already been incorporated into the synthetic arsenals of both research laboratories and industry. In addition, designing appropriate analogues to transition states and intermediates should soon make it possible, with the aid of the mammalian immune system and gene technology, to prepare catalytically active monoclonal antibodies for almost any reaction; perhaps, more important, such processes will increasingly come to be applied on an industrial scale.‐The discovery of truly new reactions is likely to be limited to the realm of transition‐metal organic chemistry, which will almost certainly provide us with additional “miracle reagents” in the years to come. As regards main group elements (“organoelemental chemistry”), we can surely anticipate further stepwise improvements in experimental procedures and the broader application of special techniques, leading to undreamed of efficiency and selectivity with respect to known procedures. The primary center of attention for all synthetic methods will continue to shift toward catalytic and enantioselective variants; indeed, it will not be long before such modifications will be available with every standard reaction for converting achiral educts into chiral products. Analysis, spectroscopy, structure determination, theory, and electronic data processing have all become indispensable in organic synthesis. Only with the aid of these “tools” will the methods of organic chemistry permit selective syntheses of ever larger and more complex systems on both the molecular and supramolecular levels.—Examples have been introduced throughout this discourse to illustrate its many themes, and a very comprehensive bibliography should help the interested reader become more familiar with important keywords and authors.[ ]—This article will have served its intended purpose if it changes the minds of some of those who claim organic chemistry is a mature science, and if it causes students to discover the vitality and forcefulness with which organic synthesis is meeting new challenges and attempting to fulfill old dreams. Er zeigt uns so in seinem wissenschaftlichen Leben, daß die Chemie nicht von einer Theorie, nicht von einer Methode aus zu erschöpfen ist, und daß Erkenntnis und Nutzen in ihr untrennbar verwoben sind. R. Koch, writing about Louis Pasteur

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“…In spite of the high synthetic potential of 4,4‐disubstituted cyclohexadienones, these multifunctional materials have hardly been exploited in asymmetric synthesis 2. Their use in domino Michael type additions for the synthesis of polycyclic compounds3 is limited to a report from our laboratory: heterocyclic cage compounds were synthesized stereoselectively from [(S) R ]‐[( p ‐tolylsulfinyl)methyl]‐ p ‐quinols or the analogous p ‐quinamines4 upon reaction with 2‐trimethylsilyloxyfuran, which initially acts as a nucleophile. The ambident nature of p ‐quinamines suggested that a domino sequence could be initiated by taking advantage of the nucleophilic amino group.…”

Section: Reactions Of 1 With Enones In the Presence Of Licl[a]mentioning

confidence: 99%

Titanium-Promoted Stereoselective Synthesis of Hydroindolones fromp-Quinamines by Domino Conjugate Additions

2002

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Stereozentren im Multipack: Bei der [TiCl2(OiPr)2]‐katalysierten Reaktion von [(S)R]‐[(p‐Tolylsulfinyl)methyl]‐p‐chinamin 1 mit den α,β‐ungesättigten Ketonen 2 zu den Hydroindol‐substituierten Systemen des Typs 3 werden in einem Domino‐Prozess neue Stereozentren erzeugt – bis zu vier bei Verwendung von Cycloalkenonen und bis zu fünf, wenn acyclische Enone (2 Äquiv.) eingesetzt werden (siehe Schema).

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One-step synthesis of tricyclo[5.3.1.0^3,8]undecan-4,11-diones by three consecutive Michael reactions. A formal synthesis of (±)-seychellene

Abstract: Divinylketone and the trimethylsilyl enol ethers of cyclohex-2-en-I -ones undergo Lewis acid assisted triple Michael reactions yielding tricyclo[5.3.1.03~*]undecan-4,11 -diones; the application of this reaction enabled a formal synthesis of (+)-seychellene (5).

Cited by 20 publications

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Domino Reactions in Organic Synthesis

Domino Reactions in Organic Synthesis

Organic Synthesis—Where now?

Titanium-Promoted Stereoselective Synthesis of Hydroindolones fromp-Quinamines by Domino Conjugate Additions

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One-step synthesis of tricyclo[5.3.1.03,8]undecan-4,11-diones by three consecutive Michael reactions. A formal synthesis of (±)-seychellene

Abstract: Divinylketone and the trimethylsilyl enol ethers of cyclohex-2-en-I -ones undergo Lewis acid assisted triple Michael reactions yielding tricyclo[5.3.1.03~*]undecan-4,11 -diones; the application of this reaction enabled a formal synthesis of (+)-seychellene (5).

Cited by 20 publications

References 0 publications

Domino Reactions in Organic Synthesis

Domino Reactions in Organic Synthesis

Organic Synthesis—Where now?

Titanium-Promoted Stereoselective Synthesis of Hydroindolones fromp-Quinamines by Domino Conjugate Additions

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Product

Resources

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One-step synthesis of tricyclo[5.3.1.0^3,8]undecan-4,11-diones by three consecutive Michael reactions. A formal synthesis of (±)-seychellene