Several macrolides were readily prepared from trimethylsilyl ω-trimethylsilyloxycarboxylates by the use of dipropylboryl trifluoromethanesulfonate (triflate) as a catalyst in good yields.
An effective method for the synthesis of carboxylic esters and lactones using substituted benzoic anhydrides with Lewis acid catalysts
作者:Isamu Shiina
DOI:10.1016/j.tet.2003.12.013
日期:2004.2
benzoic anhydride having electron withdrawing substituent(s) is developed by the promotion of Lewis acidcatalysts. In the presence of a catalytic amount of TiCl2(ClO4)2, various carboxylic esters are prepared in high yields through the formation of the corresponding mixed-anhydrides from 3,5-bis(trifluoromethyl)benzoic anhydride and carboxylic acids. The combined catalyst consisting of TiCl2(ClO4)2 together
Facile Synthesis of Lactones from Silyl ω-Siloxycarboxylates Using<i>p</i>-Trifluoromethylbenzoic Anhydride and a Catalytic Amount of Active Lewis Acid
The lactonization of silyl ω-siloxycarboxylates is successfully carried out under mild conditions in good to high yields by using p-trifluoromethylbenzoic anhydride and a catalytic amount of active acidic species generated in situ from TiCl4 and AgClO4.