RUTHENIUM-CATALYZED [2+2] CROSS-ADDITION OF NORBORNENE DERIVATIVES AND DIMETHYL ACETYLENEDICARBOXYLATE

Bicyclo[2.2.1]hept-2-ene and its derivatives react with dimethyl acetylenedicarboxylate in the presence of ruthenium complex catalysts in benzene at 80-100°C to give [2+2] cross adducts, exo-tricyclo[4.2.1.02.5]non-3-ene derivatives. RuH2(CO)[P(p-PhF)3]3, RuH2(CO)(PPh3)3, RuH2 (PPh3)4, and (cyclooctatriene)(cyclooctadiene)-ruthenium are effective catalysts. The reaction of 7-oxabicyclo[2.2.ljhept-2-enes affords 9-oxa-exo-tricyclo-[4.2.1.02,5]non-3-enes. The 1:2 mixture of cyclopentadiene or fur an derivatives and dimethyl acetylenedicarboxylatealso gives the corresponding tricyclo[4.2.1,02,5]nonene derivatives in the presence of the catalysts. Novel linear hexa and heptacyclo compounds were prepared by using this reaction. © 1979, American Chemical Society. All rights reserved.