Dihydroboration of cyclic allenes

Mehrotra, I. ; Bhagwat, M. M. ; Devaprabhakara, D. (1977) Dihydroboration of cyclic allenes Proceedings of the Indian Academy of Sciences, Section A, 86 (1). pp. 15-23. ISSN 0370-0089

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Official URL: http://www.ias.ac.in/j_archive/proca/86/1/15-23/vi...

Related URL: http://dx.doi.org/10.1007/BF03046648


The study on the dihydroboration of a large ring cyclic allene, 1,2-cyclotridecadiene and the smallest stable allene, 1,2-cyclononadiene is described. For example, a mixture of products containing isomeric cyclotridecene, bicyclo(10.1.0)-tridecane, cyclotridecanone, cyclotridecanol, isomeric cyclic 1,2-cyclotridecandiol and isomeric 1,3-cyclotridecandiol is obtained from dihydroboration-oxidation of 1,2-cyclotridecadiene. However, dihydroboration-hydrolysis-oxidation of 1,2-cyclotridecadiene affords mainly cyclotridecanol, whereas dihydroboration-oxidation with chromium trioxide-pyridine yields mainly a mixture of Z- and E-cyclotridecene. Reasonable mechanistic pathways have been suggested for the formation of products. The proposed unusual elimination reaction of 1,2-diorganoboranes with chromium trioxide has been substantiated using an authentic 1,2-diorganoborane from diphenyl acetylene. The reaction appears to be stereospecific withthreo-diorganoborane furnishing predominantly E-alkene. The results with 1,2-cyclononadiene has also been rationalised on a similar basis.

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
Keywords:Cyclic Allenes; Dihydroboration; Diorganoboranes; a Novel Elimination Reaction
ID Code:28374
Deposited On:15 Dec 2010 12:09
Last Modified:17 May 2016 11:30

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