Ring Opening Of Cyclopropyl Ketones Research Articles

Generation and [2,3]-Sigmatropic Rearrangement of Ammonium Ylides from Cyclopropyl Ketones for Chiral Indolizidines with Bridgehead Quaternary Stereocenters.

A sequence of nucleophilic ring opening of cyclopropyl ketones, N-quaternization, deprotonation, and [2,3]-sigmatropic rearrangement of ammonium ylides has been developed. This method enables efficient synthesis of bicyclic indolizidines bearing bridgehead aza-quaternary stereocenters from easily available chiral cyclopropyl ketones. The reactions proceeded with an excellent level of chirality transfer and tolerated various functional groups, providing a diverse array of allenyl- or allyl-substituted indolizidines with high enantiomeric purities (up to >99% ee).

Nickel-Catalyzed Reductive Coupling of γ-Metalated Ketones with Unactivated Alkyl Bromides.

A nickel-catalyzed reductive cross-coupling reaction of aryl cyclopropyl ketones with easily accessible unactivated alkyl bromides to access aryl alkyl ketones has been developed. This strategy facilitates access to various of γ-alkyl-substituted ketones via ring opening of cyclopropyl ketones (26 examples, 50-90% yield). Initial mechanistic studies revealed that the reaction proceeds via radical cleavage of the alkyl bromide.

Scandium-Catalyzed Enantioselective Ring-Opening of Cyclopropyl Ketones with Indoles

Scandium-Catalyzed Enantioselective Ring-Opening of Cyclopropyl Ketones with Indoles

In situ halo-aldol reaction of aldehydes with cyclopropyl ketone promoted by Mgl2 etherate

A facile synthesis of α-iodoethyl-β-hydroxyketones via the Mgl2 etherate-mediated ring opening of cyclopropyl ketones was reported using mild condition.

In situ halo-aldol reaction of aldehydes with cyclopropyl ketone promoted by MgI2 etherate

A facile synthesis of α-iodoethyl-β-hydroxyketones via the Mgl 2 etherate-mediated ring opening of cyclopropyl ketones was reported using mild condition.

ChemInform Abstract: Photochemical Ring Opening of Cyclopropyl Ketones Induced by Electron Transfer.

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Photochemical ring opening of cyclopropyl ketones induced by electron transfer

Irradiation of substituted bicyclo[n.1.0]alkan-2-ones at 254 nm in the presence of triethylamine and lithium perchlorate (LiClO 4) can lead to cyclopropane ring opening with cleavage of the C(1)-C(n+2) (ring enlargement) or C(1)-C(n+3) bonds.

Reductive ring opening of cyclopropyl ketones with samarium (II) diiodide

AbstractFunctionalized cyclopropyl ketones have been found to undergo facile reductive cyclopropane ring opening with samarium (II) diiodide in the presence of a proton source. These reactions were exceedingly rapid, taking place in most cases at −78°C under neutral conditions. An ester group substituted at the C2 position of the cyclopropane ring played an important role in the ring opening of cyclopropyl ketones.

Silicon-assisted ring opening of cyclopropyl ketones with boron trifluoride-acetic acid complex.

2-(Trimethylsilylmethyl) cyclopropyl ketones were smoothly cleaved with boron trifluorideacetic acid complex under mild reaction conditions with the assistance of the trimethylsilyl group to give γ, δ-enones in good yields. The major effect of the trimethylsilyl group in the ring opening of the cyclopropyl ketones was unambiguously confirmed in the dicyclopropyl ketone 15 : one of its two cyclopropyl rings, which has a trimethylsilylmethyl group, was selectively cleaved. Furthermore, the reaction was applied to the formal total synthesis of cis-jasmone.

Ring opening of cyclopropyl ketones by trimethylsilyl iodide

Ring opening of cyclopropyl ketones by trimethylsilyl iodide