Treatment of 1,2-(E,E)-di(1-buta-1,3-dienyl)cyclohexanol (21) with potassium hydride in tetrahydrofuran at room temperature resulted in the facile formation of a 14-membered ring dienolate which on kinetic protonation provided cyclotetradeca-3,5,7-trien-1-one. This novel rearrangement which provides the basis for an efficient, eight unit ring expansion method was also observed when 5,8-dimethyl-5-hydroxy-1,3,7,9-decapentaene (28), the acyclic analogue of 21, was treated with potassium hydride in tetrahydrofuran. Methodology for the preparation of 21 and 28 including the preparation of 1-lithio-1,3-butadiene is also described. © 1981.
Wender, P. A., Sieburth, S. M. N., Petraitis, J. J., & Singh, S. K. (1981). Macroexpansion methodology. Medium ring synthesis based on an eight unit ring expansion process. Tetrahedron, 37(23), 3967–3975. https://doi.org/10.1016/S0040-4020(01)93271-5