反应详情

A solution of 20 g of 2,7,9,9-tetramethyl-1,4-dioxaspiro[4,5]dec-6-en-8-one (prepared by the method of Example III) in hexane is stirred while a solution of n-butyl lithium in hexane is added dropwise. When no additional exotherm occurs, the addition is stopped and the mixture is stirred for about 15 minutes. Water is added with stirring to hydrolyze the lithium salt. The organic layer is separated, and the hexane is allowed to evaporate leaving oily crystals which are recrystallized from cyclohexane yielding 10 g of 4-butyl-4-hydroxy-3,5,5-trimethyl-2-cyclohexen-1-one, melting point 90°-93° C. The compound exhibits the following spectral characteristics:

1. additionis added dropwise
2. additionthe addition
3. stirringwith stirring
4. customThe organic layer is separated
5. customto evaporate
6. customleaving oily crystals which
7. customare recrystallized from cyclohexane yielding 10 g of 4-butyl-4-hydroxy-3,5,5-trimethyl-2-cyclohexen-1-one, melting point 90°-93° C