Cyclopropanones from the oxidation of hindered [4]- and [5]-cumulenes with epoxidation reagents

Crandall, Jack K.; Coppert, David M.; Schuster, Thomas; Feng, Lin

doi:10.1021/ja00041a014

Cited by 26 publications

(6 citation statements)

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“…The oxidation of a [5]cumulene via epoxidation has been described by Crandall and coworkers (Scheme 16). 157 For example, the reaction of [5]tBu with m-CPBA gives a cyclopropanone intermediate, which goes on to give an allenic ester as the product. Epoxidation with dimethyldioxirane gives the cyclopropanone as a stable product, which can then be used to form [4]tBu through either thermal or photochemical loss of carbon monoxide.…”

Section: Miscellaneous Reactionsmentioning

confidence: 99%

Synthesis and properties of long [n]cumulenes (n≥ 5)

2014

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Molecules composed of a contiguous sequence of double bonds, the [n]cumulenes, share structural similarities to both of their conjugated relatives, the polyenes and polyynes. The synthesis and properties of [n]cumulenes are, however, quite different from those of either polyenes or polyynes. At an infinite length, [n]cumulenes would provide one structural form of the hypothetical sp-hybridized carbon allotrope carbyne, while shorter derivatives offer model compounds to help to predict the properties of carbyne. Finally, derivatization of the π-electron framework of [n]cumulenes provides a number of different synthetic transformations, with cycloaddition reactions being the most common. In this review, both historical and recent synthetic achievements toward long [n]cumulenes (n ≥ 5) are discussed. This is followed by a description of our current understanding of the physical and electronic structure of [n]cumulenes based on UV/vis spectroscopy and X-ray crystallography. Finally, the reactivity of long [n]cumulenes is described.

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Section: Miscellaneous Reactionsmentioning

confidence: 99%

Synthesis and properties of long [n]cumulenes (n≥ 5)

2014

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“…Alternatively, cyclopropenone 448, which was difficult to isolate and could be detected only by NMR and FTIR analysis, was proposed as an intermediate that rearranged to 447. 283 Scheme 91 Synthesis of integrastatins through an oxidation cascade using 9 (in situ). 270,271 Scheme 92 Reaction pathways of N-acylindole.…”

Section: Oxidation/epoxidation Of Allenes and Cumulenesmentioning

confidence: 99%

“…Dioxiranes are sensitive toward steric effects, and a chiral center at the allylic position to a double bond will provide the Scheme 95 Epoxidation of cumulenes with DMDO. 283 Scheme 96 Epoxidation of bisallene with 9. 284 Scheme 97 Oxidation of phenylpropiolic acid with in situ generated 9.…”

Section: Kinetic Resolutionmentioning

confidence: 99%

“…The former was an orange colored solid that was stable under dark conditions (Scheme 95). 283 However, when exposed to light or heat, or kept in acetone solution at rt (dark), it lost carbon monoxide to form tetracene 449 . Alternatively, cyclopropenone 448 , which was difficult to isolate and could be detected only by NMR and FTIR analysis, was proposed as an intermediate that rearranged to 447 .…”

Section: Applications Of Dioxiranes In Organic Synthesismentioning

confidence: 99%

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Dioxiranes: a half-century journey

El‐Assaad¹,

Zhu²,

Sebastian³

et al. 2022

Org. Chem. Front.

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“…78 Sterically hindered cumulenes, which are converted into cyclopropanones upon a rearrangement of intermediate oxiranes, represent a peculiar system as regards epoxidation by peroxy acids. 81 A probable mechanism for this reaction is shown below:…”

Section: Specific Features Of Epoxidation Of Cycloalkenes and Methyle...mentioning

confidence: 99%

Mechanism of the directing influence of functional groups and the geometry of reactant molecules on peroxide epoxidation of alkenes

Dryuk¹,

Карцев²

1999

Russ. Chem. Rev.

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The influence of steric and electronic factors on the reactivity and the stereochemical outcome of epoxidation of cycloalkenes and prochiral alkenes by alkyl hydroperoxides, peroxy acids, oxaziridines, dioxiranes and dimethyl-a-peroxy lactone is analysed comparatively and generalised. The distinctive features of the directing influence of functional groups on the stereochemistry of the epoxide ring closure in the series of ionic, radical and molecular reactions are demonstrated. Some variants alternative to known reaction mechanisms are proposed. The bibliography includes 114 references.

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Cyclopropanones from the oxidation of hindered [4]- and [5]-cumulenes with epoxidation reagents

Cited by 26 publications

References 0 publications

Synthesis and properties of long [n]cumulenes (n≥ 5)

Synthesis and properties of long [n]cumulenes (n≥ 5)

Dioxiranes: a half-century journey

Mechanism of the directing influence of functional groups and the geometry of reactant molecules on peroxide epoxidation of alkenes

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