M. Baird, H. Hussain
1989
Citations
0
Influential Citations
19
Citations
Journal
Tetrahedron
Abstract
Abstract Reaction of 2-bromo-1, 1, 2-trichloro-3, 3-dimethylcyclopropane with one mol.equiv. of methyl lithium at −90 to 0°C leads to 1,2-dichloro-3,3-dimethylcyclopropene. This is stable for several hours at 20°C in chloroform or benzene solution but in the presence of an electron-rich or electron-poor alkene reacts in 15 m to 2 h under these conditions to give products apparently derived by reaction of these with 1,2-dichloro-3-methylbut-2-en-1-ylidene (4). The corresponding products are also obtained when 1,1,2-trichloro- or 1,1,2,2-tetrachloro-3,3-dimethylcyclopropanes are treated with methyl lithium in the presence of alkenes at 0 – 20°C. The cyclopropene (3) is stable in ether solution for more than 10 days at −30°C, but at ambient temperature reacts in 18 h to give the product of insertion of the carbene (4) into the CH bonds adjacent to oxygen.