1,3-Cyclohexandione derived cyclic ketals and thiol ketals were used as O- and S-nucleophiles, respectively, for the ring opening of donor–acceptor cyclopropanes catalyzed by Cu(OTf)2 and a series of functionalized alkylene glycol diethers and dithiol diethers were obtained in good to high yields under mild conditions.
In the reaction of 2-ethoxy-1,3-oxathiolane with carbonylcompounds in the presence of ZnCl2 or HgCl2, it has been found that only the breaking of the endocyclic bond (C–O or C–S bond) occurs, while the breaking of the exocyclic C–O bond to give the 1,3-oxathiolan-2-ium ion is unfavorable. This behavior is different from that of 2-ethoxy-1,3-dithiolane, in which the breaking of the endocyclic C–S bond