N-Alkylation of iodo lactams with reactive alkylhalides, or of the derived selenide lactams with less reactive alkylhalides, leads to substrates for free radical initiated cyclization to pyrrolizidinones and indolizidinones, e. g. 2 → 3. The first examples of iodide / vinyl bromide, selenide / aldehyde, and selenide / vinyl chloride radical cyclizations are described.
Acyl-CoA: cholesterol O-acyl transferase (ACAT) inhibitors. 1. 2-(Alkylthio)-4,5-diphenyl-1H-imidazoles as potent inhibitors of ACAT
作者:Neil V. Harris、Andrew W. Bridge、Raymond C. Bush、Edward C. J. Coffee、Donald I. Dron、Mark F. Harper、Michael J. Ashton、David J. Lythgoe、Christopher Smith
DOI:10.1021/jm00101a016
日期:1992.11
potent, bioavailable ACAT inhibitor may have beneficial effects in the treatment of atherosclerosis by (i) reducing the absorption of dietary cholesterol, (ii) reducing the secretion of very low density lipoproteins into plasma from the liver, and (iii) preventing the transformation of arterial macrophages into foam cells. We have found that a mevalonate derivative 2, which contains a 4,5-diphenyl-1H-imidazol-2-yl
A new and general method of iodine-mediated cyclization reactions of unsaturated carbamates, ureas and amides which gives N-cyclized products as a single regio-isomer was achieved. The present reaction proceeds in good yield through regio-control of an ambidentnucleophile by LiAl(Ot-Bu)4, and the regio-control (N-attack vs O-attack) was also found to be remarkably affected by the additive employed
A new and general method of iodine-mediated cyclization reactions of allyl or homoallyl carbamates, ureas, and amides was found to give N-cyclized products as single regioisomers. The present reaction proceeded in good yield through regiocontrol (N-cyclization > O-cyclization) and the increase in the reactivity of an ambident nucleophile by a basic metallic reagent. The N-cyclization selectivity was