Enantioselective intramolecular cyclopropanation of α-diazo-β- keto sulfones: Asymmetric synthesis of bicyclo[4.1.0]heptanes and tricyclo[]decenes

Masahiro Honma, Masahisa Nakada

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Catalytic asymmetric synthesis of some new chiral building blocks useful for natural product synthesis is described. The intramolecular cyclopropanation (IMCP) reaction of α-diazo-β-keto sulfones affording bicyclo[4.1.0]heptanes such as 9a-d is found to proceed with high enantioselectivity (93-98% ee). The yield is moderate due to the competing intramolecular C-H insertion reaction. As intramolecular C-H insertion reaction is not observed in the reaction of the substrates possessing a quaternary carbon at the allylic position, the reactions of 19a and 19b proceed with high enantioselectivity (95% ee) and yield. It was also found that the substrates possessing an ether group, such as 19a and 19b, could be used in this enantioselective IMCP reaction.

Original languageEnglish
Pages (from-to)9007-9011
Number of pages5
JournalTetrahedron Letters
Issue number50
Publication statusPublished - 2003 Dec 8



  • Asymmetric synthesis
  • Cyclopropanation
  • Enantioselection
  • Intramolecular reaction

ASJC Scopus subject areas

  • Biochemistry
  • Drug Discovery
  • Organic Chemistry

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