PALLADIUM-CATALYZED CARBONYLATIVE LACTONIZATION OF PROPARGYL ALCOHOLSWITH ORGANIC DICHALCOGENIDES AND CARBON-MONOXIDE

The reaction of propargylic alcohols with diaryl disulfides and carbon monoxide in the presence of tetrakis(triphenylphosphine)palladium lea ds to a novel thiolative lactonization to afford beta-(arylthio)alpha, beta-unsaturated lactones in moderate to good yields. Similar conditio ns can be employed with homopropargylic alcohols, giving the correspon ding delta-lactones with a beta-arylthio group successfully. The react ion using diaryl diselenides in lieu of diaryl disulfides also attains a similar one-pot thiolation/lactonization sequence to provide the co rresponding beta-selenobutenolides (7).