1156487-93-2Relevant academic research and scientific papers
A highly efficient macrolactonization method via ethoxyvinyl ester
Ohba, Yusuke,Takatsuji, Mayuko,Nakahara, Kenji,Fujioka, Hiromichi,Kita, Yasuyuki
experimental part, p. 3526 - 3537 (2009/12/31)
We present the highly efficient reaction procedure of the macrolactonization method via ethoxyvinyl esters (EVEs). The following procedure was performed: 1)The EVE was prepared from hydroxycarboxylic acid and ethoxyacetylene in the presence of the Ru catalyst [RuCl2(p-cymene)] 2 in acetone; 2) after filtration of the Ru catalyst through a short-neutral SiO2 pad and evaporation of acetone, the EVE formed was diluted in 1,2-dichloroethane (DCE) and the solution was slowly added by a syringe pump to the highly diluted DCE solution of pTsOH (10mol%) at 80°C. Varioussized lactones could be produced by the method described here. It is note worthy that the method can give 9- to 14-membered macrolactones in good yields. This macrolactonization method via EVEs is useful for acid-/base-sensitive substrates. Furthermore, it was found that EVE formation was possible without loosing activity of the Ru catalyst even for the compounds with nucleophilic amine functions. The characteristic feature of the method was exemplified by the reaction of the compound 14 with many functional groups.
