Samarium diiodide mediated 6-exo cyclisations of methylenecyclopropyl ketones
作者:Jonathan J. Underwood、Gregory J. Hollingworth、Peter N. Horton、Michael B. Hursthouse、Jeremy D. Kilburn
DOI:10.1016/j.tetlet.2003.12.156
日期:2004.3
6-exo Cyclisations of methylenecyclopropyl ketones, mediated by samariumdiiodide, have been investigated with a series of substrates. The efficiency of the cyclisations are highly dependent on the stereochemistry of the cyclisation precursor.
Lewis acid mediated cascade reactions of silyl-substituted methylenecyclopropyl ketones
作者:Guillaume L.N Peron、John Kitteringham、Jeremy D Kilburn
DOI:10.1016/s0040-4039(99)02342-4
日期:2000.3
cyclisation of various silyl-substituted methylenecyclopropylketones has been investigated. The presence of the silyl-substituent enhances the reactivity of the methylene cyclopropane in comparison to our earlier study on non-silyl-substituted methylenecyclopropylketones, allowing milder Lewis acids (BF3·Et2O or BF3·2AcOH) to be used for the cyclisation reaction. The mild conditions used allow the allyl
Lewis acid mediated cyclisation of methylenecyclopropyl ketones and aldehydes
作者:Guillaume L.N. Peron、John Kitteringham、Jeremy D. Kilburn
DOI:10.1016/s0040-4039(99)00320-2
日期:1999.4
The Lewis acid mediated cyclisation of various methylenecyclopropyl ketones, ketals and aldehydes has been investigated as a new route to six- and seven-membered rings. Cyclisation of aldehyde 6, ketal 9 and ketone 11 with TiCl4 gave cyclohexene products, and cyclisation of ketal 10 gave a dichlorocycloheptene, all via nucleophilic addition of the methylenecyclopropyl π bond to the activated carbonyl