Synthesis of gamma-butyrolactones using radical cyclization on solid-phase
has been achieved. Polymer-supported beta-bromoethylacetals were treated wi
th tributyltin hydride in the presence of a catalytic amount of alpha,alpha
'-azobisisobutyronitrile to generate intermediate carbon radicals which cyc
lize onto the intramolecular carbon-carbon double bond. The cyclization pro
ducts were released by Jones oxidation from resin to give gamma-butyrolacto
nes in good yields. (C) 1999 Elsevier Science Ltd. All rights reserved.