Synthesis of medium-sized cyclic γ-haloketones by radical mediated ring-opening reaction of Lewis acid catalyzed (2+2)-cycloaddition products
作者:Kiyosei Takasu、Satoshi Nagao、Masataka Ihara
DOI:10.1016/j.tetlet.2004.12.024
日期:2005.2
Novel entry to synthesize medium-sized cycloalkanones is described. Thus, employment of catalytic (2+2)-cycloaddition for cyclic silyl enol ether followed by radical mediated ring-openingreaction provided medium-sized γ-halocycloalkanones.
An efficient catalytic (2 + 2)-cycloaddition reaction leading to the formation of cyclobutane rings has been devised. The process transforms silyl enol ethers and α,β-unsaturated esters into polysubstituted cyclobutanes with a high degree of trans-stereoselectivity. Both the rate and stereoselectivity of the process can be controlled by the choice of the ester group and silyl substituents. The results