A short synthesis of 3-oxa- and 3-azabicyclo[3.1.0]hexanes from α,β-unsaturated esters based on the 1,5-CH insertion reaction of cyclopropylmagnesium carbenoids

✍ Scribed by Tsuyoshi Satoh; Shotaro Ikeda; Toshifumi Miyagawa; Takafumi Noguchi

• Publisher: Elsevier Science
• Year: 2010
• Tongue: French
• Weight: 405 KB
• Volume: 51
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2010.02.010

✦ Synopsis

1-Chlorocyclopropyl p-tolyl sulfoxides bearing an alkoxymethyl group at the 2-position were easily prepared from a,b-unsaturated esters with dichloromethyl p-tolyl sulfoxide and alkylhalides in three steps in good overall yields. Treatment of the 1-chlorocyclopropyl p-tolyl sulfoxides with i-PrMgCl resulted in the formation of 3-oxabicyclo[3.1.0]hexanes in up to 89% yield as a single diastereomer via the 1,5-CH insertion reaction of the generated cyclopropylmagnesium carbenoid intermediates. This procedure provides a good way for the synthesis of 3-oxabicyclo[3.1.0]hexanes from a,b-unsaturated esters in only four steps. 3-Aza-and 3-thiabicyclo[3.1.0]hexanes were also obtained from the corresponding precursors via the 1,5-CH insertion reaction of the cyclopropylmagnesium carbenoid intermediates, though the yields were low to moderate.