Abstract
N-Acetyl-N′-methyl urea or ethyl urea in the presence of an acetylenic ester and a desired phosphine functioned as a NH-acid and added to the triple bond in a chemoselective reaction. One of the obtained products underwent lactonization to the corresponding imidazolidine containing ylide moiety when heated in the presence of a base such as triethyl amine.
We thank the Shahid Bahonar University for financial support as a Grant-in-Aid for Scientific Research.