Alkylation of acetylcyclopropane cyclohexylimine by ethylene oxide derivatives as a key step in the synthesis of some insect acetogenin pheromones
摘要:
The interaction of Li derivatives of acetylcyclopropane cyclohexylimine with ethylene, propylene, and isoprene oxides leads efficiently to the corresponding gamma-cyclopropylketols. The cyclopropylcarbinol corresponding to the first of them is smoothly converted under the action of the couple Me3SiBr/ZnBr2 to a linear E-C7-homoallyl bromide, which is then used in the stereocontrolled synthesis of tridec-4E-enyl and trideca-4E, 7Z-dienyl acetates - components of the sex pheromones of some Lepidoptera species.
Switching between Novel Samarium(II)-Mediated Cyclizations by a Simple Change in Alcohol Cosolvent
作者:Thomas K. Hutton、Kenneth W. Muir、David J. Procter
DOI:10.1021/ol0358399
日期:2003.12.1
undergo two very different stereoselective cyclization reactionsmediated by samarium(II) iodide depending upon the alcohol cosolvent used in the reaction. Switching between an unprecedented aldol spirocyclization and a novel cyclobutanol-forming process can be achieved simply by changing the alcohol cosolvent from methanol to tert-butyl alcohol. [reaction: see text]