Novel Efficient Synthesis of 1-Ethoxyvinyl Esters Using Ruthenium Catalysts and Their Use in Acylation of Amines and Alcohols: Synthesis of Hydrophilic 3'-N-Acylated Oxaunomycin Derivatives
A novel and efficient synthesis of 1-ethoxyvinyl esters 3a-i from carboxylic acids 4a-i and ethoxyacetylene 5 by using a catalytic amount of ruthenium complex 2> 6f has been developed.These reagents reacted smoothly with amines and alcohols to give the corresponding N- and O-acylated compounds in excellent yields.This acylation method has been applied to the synthesis of hydrophilic 3'-N-acylated oxaunomycin derivatives 13a,b.