The reaction of gem-dibromocyclopropanes 5 with nBu(3)MgLi affords butylated cyclopropylmagnesium species that can be trapped with various electrophiles. The reaction of dibromomethylsilanes 12 requires the addition of a catalytic amount of CuCN.2LiCl for smooth migration of the alkyl groups. The resultant alpha-silylpentylmagnesium compounds 16 react with electrophiles, such as acyl chlorides or alpha.beta-unsaturated ketones to afford alpha- or gamma-silyl ketones, respectively. Treatment of dibromodisilylmethanes with Me3MgLi yields 1-bromo-1,1-disilylethanes 25 that can be converted into 1,1-disilylethenes 29 by dehydrobromination.
Spiroannelation via gem-dihalocyclopropane substrates and a cyclocuprate species
作者:Federick Scott、Brownlee G Mafunda、Jean F. Normant and Alexandre Alexakis
DOI:10.1016/s0040-4039(00)94196-0
日期:1983.1
SCOTT, F.;MAFUNDA, B. G.;NORMANT, J. F.;ALEXAKIS, A., TETRAHEDRON LETT., 1983, 24, N 51, 5767-5770
作者:SCOTT, F.、MAFUNDA, B. G.、NORMANT, J. F.、ALEXAKIS, A.
DOI:——
日期:——
Lithium norcaranylidenoids. Alkylation and epimerization
作者:Philip M. Warner、Suae-Chen Chang、Nicholas J. Koszewski
DOI:10.1016/s0040-4039(00)98210-8
日期:1985.1
The epimeric 7-bromo-7-lithionorcaranes have been stereospecifically generated; the -bromo isomer is stable at −78°C, while the - bromo isomer is reactive. The stereochemistry of itsreaction with nBuLi involves inversion.