Incorporation of an allene unit into alpha-pinene: Generation of the cyclic allene 2,7,7-trimethylbicyclo[4.1.]octa-2,3-diene and its dimerization

Date

2004-02-20

Author

Azizoglu, A
Ozen, R
Hokelek, T
Balcı, Metin

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The reaction of etheral methyllithium with 3,3-dibromo-2,7,7-trimethyl-tricyclo[4.1.1.0.(2,4)] octane (2) was investigated. The generated carbene 12 undergoes intramolecular C-H insertion to provide the tetracyclic hydrocarbon 3 and the bicyclic allene 15, which undergoes [2 + 2] cyclodimerization. The structures of the formed allene dimers 16, 17, and 18 were elucidated by spectral means. The activation barriers for all possible C-H insertion products 3, 13, and 14 and the allene 15 were investigated by using density functional theory computations at the B3LYP/6-31G(d) level. It was found that the activation barriers for the formation of 3 and 15 (6.2 and 6.3 kcal mol(-1)) are much lower than that for the insertion products 13 and 14 (17.5 and 12.6 kcal mol(-1)), respectively. This prediction was completely in agreement with our experimental results.

Subject Keywords

Organic Chemistry

URI

https://hdl.handle.net/11511/57304

Journal

JOURNAL OF ORGANIC CHEMISTRY

DOI

https://doi.org/10.1021/jo035450z

Collections

Graduate School of Natural and Applied Sciences, Article

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Citation Formats

A. Azizoglu, R. Ozen, T. Hokelek, and M. Balcı, “Incorporation of an allene unit into alpha-pinene: Generation of the cyclic allene 2,7,7-trimethylbicyclo[4.1.]octa-2,3-diene and its dimerization,” JOURNAL OF ORGANIC CHEMISTRY, pp. 1202–1206, 2004, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/57304.