The EtAlCl2-mediated intramolecular addition of silyl enol ethers to both terminal and internal unactivatedalkynes, bearing alkyl and phenyl susbstituents at the alkyne moiety, proceeded exclusively in the endo-fashion to give mono- and bicyclic β,γ-unsaturated ketones in good to excellent yields. The mechanism of this regiospecific Lewis acid-assisted carbocyclization is proposed.
A ONE-POT AND SELECTIVE PREPARATION OF ALKYLATED 3-CYCLOHEXEN-1-ONE
作者:Kunihiko Takabe、Suguru Ohkawa、Takao Katagiri
DOI:10.1246/cl.1981.489
日期:1981.4.5
Treatment of lithiated nitrile with conjugated 1,3-dienes, such as isoprene, myrcene, and butadiene, followed by hydrolysis with 3N–HC1 gave selectively alkylated 3-cyclohexen-1-ones.