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.
REGIOCHEMICAL CONTROL OF THE RING-OPENING OF 1,2-EPOXIDES BY MEANS OF CHELATING PROCESSES .9. SYNTHESIS AND RING-OPENING REACTIONS OF CIS-OXIDES AND TRANS-OXIDES DERIVED FROM 3-(BENZYLOXYMETHYL)CYCLOPENTENE AND METHYL 2-CYCLOPENTEN-1-CARBOXYLATE
CROTTI, PAOLO;DI BUSSOLO, VALERIA;FAVERO, LUCILLA;PINESCHI, MAURO
1995-01-01
Abstract
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
