1,2-cyclooctadiene, a product observed from the reaction of 8,8-dibromobicyclo[5.1.0]octane with methyllithium

✍ Scribed by E.T. Marquis; P.D. Gardner

• Publisher: Elsevier Science
• Year: 1966
• Tongue: French
• Weight: 206 KB
• Volume: 7
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)99862-4

✦ Synopsis

It is well established that the reaction between ~-dibromocycIopropcmes and methyllithium generally affords allenes (1,2,3) and evidence has been presented which suggests that a carbene or carbenoid complex is on intermediate in the process (4,5,6). The reaction of strained methylenedibromocyclopropanes presently under investigation has been observed to give a product bearing a new methyl group. This observotion prompted a study of the similar reaction of 8,8-dibromobicyclo]5.1 .O]octone (1), a system which would appear capable of giving the highly stmined and OS yet unknown 1,2-cyclcoctadiene (II) for inclusion in this study. The addition of I to ethereal methyllithium at 0' wa; observed to give five products, four of which were isolated by prepamtive gas-liquid chronxltogmphy (Ill, IV, V cmd VI).

1,2-Cyclooctodiene (II) could be detected only immediately after quenching the reaction mixture with water and was found to be present to the extent of about 8%.