Patent ID: 7071339

Claim:
A process for preparing functionalized butyrolactones of formula wherein X is Cl or Br; R 1 , R 2 , and R 3 are each independently H, halo, aryl, (C 1 –C 6 )alkoxycarbonyl, (C 1 –C 6 )alkanoyl, (C 1 –C 6 alkyl), halo(C 1 –C 6 alkyl), heteroaryl(C 1 –C 6 )alkyl or aryl (C 1 –C 6 alkyl); and “- - - ” is a bond or is absent, provided that when “- - - ” is a bond, R 1 and R 2 are absent; comprising: (a) contacting mucohalic acid 1 wherein X is as defined above; with halide 2 wherein Y is Cl, Br, or I; R 1 , R 2 , and R 3 are as defined above; and “- - - ” is as defined above; a metal selected from indium, tin or zinc; and a catalytic amount of ammonium chloride in a solvent to form the compound of formula I.