Stereospecific Cyclopropanation of Highly Substituted C-C Double Bonds Promoted by CrCl2. Stereoselective Synthesis of Cyclopropanecarboxamides and Cyclopropyl Ketones

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• 作者：José ; M. Concelló ; n ; Humberto Rodrí ; guez-Solla ; Carmen Mé ; jica ; Elena G. Blanco
• 刊名：Organic Letters
• 出版年：2007
• 出版时间：August 2, 2007
• 年：2007
• 卷：9
• 期：16
• 页码：2981 - 2984
• 全文大小：60K
• 年卷期：v.9,no.16(August 2, 2007)
• ISSN：1523-7052

文摘

We describe herein a CrCl₂-promoted cyclopropanation of ,-unsaturated amides. This reaction can be carried out on (E)- or (Z)-,-enamidesin which the C-C double bond is di-, tri-, or tetrasubstituted. In all cases the process is completely stereospecific and only a single diastereoisomeris obtained. In addition, cyclopropyl ketones were readily prepared by reaction of the cyclopropanecarboxamides (derived from morpholine)obtained with a range of organolithium compounds. A mechanism has been proposed to explain the cyclopropanation reaction.