Tetrahedron
Synthesis of medium-sized lactones by the copper (I) chloride/2, 2′-bipyridine-catalyzed cyclization of di-and trichloroacetates
FOH Pirrung, H Hiemstra, WN Speckamp, B Kaptein…
Index: Pirrung, Frank O. H.; Hiemstra, Henk; Speckamp, W. Nico; Kaptein, Bernard; Schoemaker, Hans E. Tetrahedron, 1994 , vol. 50, # 43 p. 12415 - 12442
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Citation Number: 57
Abstract
Medium-sized lactones (eight-to eleven-membered rings) are efficiently formed by Cu (bpy) Cl catalyzed cyclization of various alkenyl di-and trichloroacetates at temperatures between 80 and 190° C in 1, 2-dichloroethane or benzene as solvents. The mechanism of the alkene addition reaction is best understood as a chlorine atom transfer process through radical type intermediates. Exclusive endo-cyclization is observed in all cases. Ten and eleven- ...