Regiochemical control of the ring opening of 1,2-epoxides by means of chelating processes. 9. Synthesis and ring opening reactions of cis- and trans-oxides derived from 3-(benzyloxymethyl)cyclopentene and methyl 2- cyclopenten-1-carboxylate

Article abstract of DOI:10.1016/0040-4020(95)00425-8

The regiochemical outcome of the ring opening of 1,2-epoxides through chelation processes assisted by metal ions, was verified in the oxirane systems derived from cyclopentene bearing a polar functionality (CH₂OBn or COOMe) in a homoallylic relationship to the oxirane ring. The cis/trans diastereoisomeric epoxide pairs 7-8 and 9-10 derived from 3- (benzyloxymethyl)cyclopentene and methyl 2-cyclopenten-1-carboxylate, respectively, were prepared and some of their opening reactions were studied. The regioselectivity observed turned out to depend on the opening reaction protocol (standard or metal-assisted), suggesting the efficacious incursion, under the appropriate conditions, of chelate bidentate species in the opening process.