Cj. Xi et al., Reaction of oxazirconacyclopentenes with propynoates. A new pathway for the formation of 2,5-dihydrofuran derivatives, TETRAHEDR L, 40(12), 1999, pp. 2375-2378
Oxazirconacyclopentenes, which were easily prepared from Cp2ZrEt2, alkynes
and ketones, reacted with propynoate in the presence of CuCl to give 2,5-di
hydrofurans after hydrolysis. (C) 1999 Elsevier Science Ltd. All rights res
erved.