
TY  - JOUR
A1  - Brown, RFC 
A1  - Eastwood, FW 
A1  - Jackman, GP 
T1  - Methyleneketenes and methylenecarbenes. IX. Thermal rearrangements of Alkyl-and Aryl-acetylenes involving Alkyl- and Aryl-methylenecarbenes
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1977
VL  - 30
IS  - 8
SP  - 1757
EP  - 1767
KW  - 
UR  - https://doi.org/10.1071/CH9771757 
N2  - Flash vacuum pyrolysis of 1-(1?-adamantyl)acetylene[2-14C] (780°) gives recovered alkyne which contains 25% of the rearranged product, 1-(1?- adamantyl)acetylene[1-14C]. 1-Ethynyl-1-methylcyclohexane(740°) is converted into toluene and benzene, while evidence for rearrangement of 3,3-dimethylbut-1-yne[2-13C] (790°) and 3-methyl-3-phenylbut-1-yne[2- 13C] (680°) was not obtained before the onset of alternative reactions. These reactions of alkyl-substituted alkynes are discussed in terms of possible methylene carbene intermediates. Similar intermediates may possibly be involved in reactions of arylalkynes. Thus, pyrolysis of 1- ethynylnaphthalene (750°) yields acenaphthylene and of 1-ethynyl-8- methylnaphthalene (750°) yields phenalene. The pathways for the formation of 2-phenyl- and 3-phenyl-indene from (2- methylphenyl)phenylethyne (790°) and of indene from (2- methylphenyl)ethyne (740°) are obscured by facile thermal rearrangements. 
ER  -

