Synthesis of 12- and 13-membered sulfur-containing lactones by homolytic macrocyclization of mercaptoacetic esters with alkynes

Article abstract of DOI:10.1055/s-1995-3891

Starting from mercaptoacetic acid esters of 1,2- or 1,3-diols and substituted acetylenes 12- and 13-membered sulfur-containing lactones as 1:1 adducts were synthesised in yields up to 48%. The mechanism of this homolytic reaction, which is initiated by the tripropylborane/oxygen system, includes generation of thiyl radicals and their addition to the triple bond of alkynes.