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
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 insertionreaction of the generated cyclopropylmagnesium carbenoid intermediates. This procedure provides a good way for the synthesis of 3-oxabicyclo[3.1.0]hexanes from α,β-unsaturated esters in only four steps. 3-Aza- and 3-thiabicyclo[3.1.0]hexanes were also obtained from the corresponding
via 1,5-C–H insertion of cyclopropylmagnesium carbenoids as a key step. 1-Chlorocyclopropyl p-tolyl sulfoxides with an N,N-disubstituted aminomethyl group on the cyclopropane ring were prepared from dichloromethyl p-tolyl sulfoxide, α,β-unsaturated carboxylic acid esters, primary amines, and alkyl halides. Treatment of the sulfoxides with i-PrMgCl generated cyclopropylmagnesium carbenoids, which were
Synthesis of (2S, 3R, 4S)-3,4-methanoproline and analogues by cyclopropylidene insertion
作者:Viacheslav V. Tverezovsky、Mark S. Baird、Ivan G. Bolesov
DOI:10.1016/s0040-4020(97)00988-5
日期:1997.10
Intramolecular insertion of single enantiomers of cyclopropylidenes into 5,6-related CH bonds adjacent to nitrogen has been used to obtain enantiomerically pure methanoproline and a number of analogues with a high degree of one- or two-fold asymmetric induction.