Cyclization of 2-(2-bromoethoxy)-acetophenones and 5-(ω-haloalkoxy)-1,5-dihydro-2<i>H</i>-pyrrol-2-ones Formation of five- to eight-membered oxygen-containing heterocycles via intramolecular alkylation
作者:Kirill V Nikitin、Nonna P Andryukhova
DOI:10.1139/v04-011
日期:2004.5.1
Under basic conditions (lithium diisopropylamide or sodium hydride in THF) 2-(2-bromoethoxy)-acetophenones were transformed to 3,4-dihydro[1]benzoxepin-5(2H)-ones (homochromanones) in high yields. ...
An Efficient Synthetic Strategy for Geometrically Pure Symmetrical and Unsymmetrical Hydroxystilbenes via McMurry Coupling
作者:Subrata Chattopadhyay、Narayan V. Mayekar、Sandip K. Nayak
DOI:10.1055/s-2003-41004
日期:——
Intramolecular reductive deoxygenation of ethylene-dioxy tethered symmetrical and unsymmetrical aromatic bis(carbonyl) ethers with the low-valenttitanium (LVT) reagent (TiCl 4 -Zn-THF) yielded chromatographically separable E/Z-isomers of corresponding cyclic stilbenes which were further dealkylated to obtain geometrically pure hydroxystilbenes. The intramolecular McMurry coupling of the tethered bis(carbonyl)