نتایج جستجو برای: cyclic ketones

تعداد نتایج: 107112  

Journal: :Organic & biomolecular chemistry 2016
Jacob J Loman Emma R Carnaghan Trevor A Hamlin John M Ovian Christopher B Kelly Michael A Mercadante Nicholas E Leadbeater

The propensity of oxoammonium cations to facilitate the oxidative ring-opening of cyclic ethers to their corresponding distal hydroxy ketones is investigated. The reaction has been evaluated using experimental and computational methods to gain deeper insight into trends in reactivity.

Journal: :Chemical communications 2005
Sengodagounder Muthusamy Janagiraman Krishnamurthi Munirathnam Nethaji

The reverse regio- and diastereoselectivities are observed between the reactions involving 5- and 6-membered-ring cyclic carbonyl ylide dipoles with alpha-methylene ketones. A mild catalytic route to synthesize spirocyclic systems with high regio-, chemo- and diastereoselectivities is described.

2008
PETER YATES Lash Miller

ion from the solvent by the excited cyclocamphanone to give (XXV), cleavage of the cyclopropane ring to give (XXXVI), and hydrogen atom transfer and ketonization. This postulated route for the isomerization of cyclocamphanone to (XXXIV) is based on the proposal by Srinivasan for the route of isomerization of camphor to the ketone (XIV)'°. The photolysis of (XXXIV) to give (XVI) finds close anal...

Journal: :Canadian Journal of Chemistry 1972

Journal: :Chemical communications 2009
Zhenghu Xu Philias Daka Hong Wang

The first example of metal Lewis acid-primary amine bifunctional cooperative catalyst derived from primary amino acids was developed, and it was found to catalyze aldol reactions of cyclic ketones highly efficiently with very good to excellent stereoselectivities.

2014
Wenyong Chen Ming Chen John F. Hartwig

We report asymmetric allylic alkylation of barium enolates of cyclic ketones catalyzed by a metallacyclic iridium complex containing a phosphoramidite ligand derived from (R)-1-(2-naphthyl)ethylamine. The reaction products contain adjacent quaternary and tertiary stereocenters. This process demonstrates that unstabilized cyclic ketone enolates can undergo diastereo- and enantioselective Ir-cata...

2015
Yanfei Zhao Zhenzhen Yang Bo Yu Hongye Zhang Huanjun Xu Leiduan Hao Buxing Han Zhimin Liu

The hydration of propargylic alcohols is a green route to synthesize a-hydroxy ketones. Herein a CO2reactive ionic liquid (IL), [Bu4P][Im], was found to display high performance for catalyzing the hydration of propargylic alcohols in the presence of atmospheric CO2, and a series of propargylic alcohols could be converted into the corresponding a-hydroxy ketones in good to excellent yields. In t...

Journal: :Organic & biomolecular chemistry 2014
Yong-Ming Sun Nana Xin Zhong-Yuan Xu Li-Juan Liu Fan-Jie Meng He Zhang Bao-Ci Fu Qiu-Ju Liang Hong-Xing Zheng Li-Jun Sun Chang-Qiu Zhao Li-Biao Han

Aromatic methyl ketones and cyclic asymmetric ketones underwent hydrophosphorylation with P-stereogenic H-P species in the presence of potassium carbonate to produce P,C-stereogenic tertiary α-hydroxyl phosphinates in excellent yields with up to 99 : 1 dr. The diastereoselectivity was induced by a reversible conversion of less stable stereomer of product to that of a more stable one via an equi...

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