Medium ring unsaturated ketones: interconversions between cycloalk-2-enones and cycloalk-3-enones and related phenomena
作者:N. Heap、G. H. Whitham
DOI:10.1039/j29660000164
日期:——
Conditions under which medium-ring αβ- and βγ-unsaturated ketones can be interconverted have been established, and equilibrium constants have been determined for rings of six to nine members inclusive. Increase in ring size progressively favours the βγ-unsaturated ketone, and it is the more stable isomer in the eight and nine membered rings.
The two isomeric dibromides, obtained by the addition of bromine to cyclonona-1,2-diene (4), have been identified as 2,3-dibromo-cis-cyclononene (2; RBr) and 1,4-dibromo-cis-cyclononene (5; RBr); these compounds were obtained in the approximate relative proportions of 40:60.