Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... An extremely mild method for the transformation of propiolic esters to β-keto esters via thiol addition is reported, including its successful application to the synthesis of (±)-thienamycin. ... ) was prepared by the gradual addition of the lithium acetylide generated from to p-nitrobenzyl ...