874-35-1Relevant articles and documents
Intermediate Formation ofMetacyclophane on Flash Vacuum Thermolysis
Kostermans, Gerardus, B. M.,Dansik, Paul van,Wolf, Willem H. de,Bickelhaupt, Friedrich
, p. 4531 - 4534 (2007/10/02)
Pyrolysis of 2,6-tetramethylene Dewar benzene (2a) under flash vacuum thermolysis (FVT) conditions at 400 deg C gave 6- and 5-methylindan (8a (2.5percent) and 10a (2.5percent), respectively) as well tetralin (5a) (45percent).These products indicate that metacyclophane (1a) was formed in the gas phase, but it decomposed under the reaction conditions either via homolytic cleavage of one of the benzylic bonds to yield a diradical (6a) leading to 8a and 10a or it gave 5a via benzvalene intermediate (4a).Deuterium labeling supports the proposed mechanism.A very similar course of events was observed on FVT of metacyclophane at 600 deg C; it yielded methyl-substituted tetralins (8c, 10c) as the sole products.The analogies and differences in the behavior of the two metacyclophanes are discussed.