Macroexpansion methodology

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.