Addition of sec-alcohols to alkynes through a radical process using NHPI/CoII/O2 system

alpha-Hydroxy carbon radicals generated from alcohols by the action of NHPI smoothly added to electron-deficient alkynes like acetylenedicarboxylates. For instance, the reaction of 2-propanol with dimethyl acetylenedicarboxylate afforded maleate derivative 3, 3-methoxycarbonyl-4,4-dimethyl-2-buten-4-olide (4), and a fused bis-y-butyrolactone 5 formed by further addition of 2-hydroxy-2-propyl radical to 4.