@article {2905, title = {CRYSTAL-STRUCTURE CORRELATIONS IN THE PHOTOCHEMISTRY OF DIMETHYL 9,10-DIMETHYL-9,10-DIHYDRO-9,10-ETHENOANTHRACENE-11,12-DICARBOXYLATE}, journal = {Acta Crystallographica Section B-Structural Science}, volume = {49}, year = {1993}, note = {ISI Document Delivery No.: KM629Times Cited: 15Cited Reference Count: 25Part 1}, month = {Feb}, pages = {107-116}, type = {Article}, abstract = {{The photochemistry of the title 9,10-dimethlydi-benzobarrelene-11,12-diester (1) in solution and in the solid state exhibits unique differences as a function of reaction medium. In acetone the normal di-pi-methane reaction leads to a semibull-valene derivative, dimethyl 4b,8b-dimethy-4b,8b,8c,-8d-tetrahydrodibenzo[a,f]cyclopropa[calpentalene -gc,8d-dicarboxylate (2), while in acetonitrile an additional cyclooctatetraene (COT) photoproduct, dimethyl 5,11-dimethyldibenzo[a,e]cyclooctene-6,12-dicarboxylate (3), is obtained. In the solid state a new pentalene, dimethyl 5, 10-dimethyl-5, 10-dihydro-indeno[2,1-a]indene-5,10-dicarboxylate (4), is formed as the major product. Crystal data for (1), (3) and (4): T = 294 K, Cu Kalpha}, keywords = {1, 2-MIGRATION, EXPLORATORY ORGANIC-PHOTOCHEMISTRY, PHOTOPRODUCTS, PI-METHANE REARRANGEMENT, SOLID-STATE PHOTOCHEMISTRY, SUBSTITUTED DIBENZOBARRELENE}, isbn = {0108-7681}, url = {://A1993KM62900013}, author = {Pokkuluri, P. R. and Scheffer, J. R. and Trotter, J.} } @article {2905, title = {CRYSTAL-STRUCTURE CORRELATIONS IN THE PHOTOCHEMISTRY OF DIMETHYL 9,10-DIMETHYL-9,10-DIHYDRO-9,10-ETHENOANTHRACENE-11,12-DICARBOXYLATE}, journal = {Acta Crystallographica Section B-Structural Science}, volume = {49}, year = {1993}, note = {ISI Document Delivery No.: KM629Times Cited: 15Cited Reference Count: 25Part 1}, month = {Feb}, pages = {107-116}, type = {Article}, abstract = {{The photochemistry of the title 9,10-dimethlydi-benzobarrelene-11,12-diester (1) in solution and in the solid state exhibits unique differences as a function of reaction medium. In acetone the normal di-pi-methane reaction leads to a semibull-valene derivative, dimethyl 4b,8b-dimethy-4b,8b,8c,-8d-tetrahydrodibenzo[a,f]cyclopropa[calpentalene -gc,8d-dicarboxylate (2), while in acetonitrile an additional cyclooctatetraene (COT) photoproduct, dimethyl 5,11-dimethyldibenzo[a,e]cyclooctene-6,12-dicarboxylate (3), is obtained. In the solid state a new pentalene, dimethyl 5, 10-dimethyl-5, 10-dihydro-indeno[2,1-a]indene-5,10-dicarboxylate (4), is formed as the major product. Crystal data for (1), (3) and (4): T = 294 K, Cu Kalpha}, keywords = {1, 2-MIGRATION, EXPLORATORY ORGANIC-PHOTOCHEMISTRY, PHOTOPRODUCTS, PI-METHANE REARRANGEMENT, SOLID-STATE PHOTOCHEMISTRY, SUBSTITUTED DIBENZOBARRELENE}, isbn = {0108-7681}, url = {://A1993KM62900013}, author = {Pokkuluri, P. R. and Scheffer, J. R. and Trotter, J.} } @article {2838, title = {NOVEL PHOTOCHEMISTRY OF A STERICALLY CROWDED MONOBENZOBARRELENE DERIVATIVE}, journal = {Tetrahedron Letters}, volume = {34}, number = {1}, year = {1993}, note = {ISI Document Delivery No.: KE371Times Cited: 6Cited Reference Count: 12}, month = {Jan}, pages = {31-34}, type = {Article}, abstract = {The solution phase photochemistry of the sterically congested tetramethylated benzobarrelene derivative 2b differs completely from that of its non-methylated counterpart, 2a. Based on molecular mechanics calculations, the factor that is suggested to be responsible for this difference is relief of the unfavorable methyl-methyl interactions present in 2b.}, keywords = {3-DICARBOXYLATE, 4-DIHYDRO-1, 4-ETHENONAPHTHALENE-2, DIMETHYL 1, SOLID-STATE, SUBSTITUTED DIBENZOBARRELENE}, isbn = {0040-4039}, url = {://A1993KE37100005}, author = {Jones, R. and Scheffer, J. R. and Trotter, J. and Yap, M.} } @article {2838, title = {NOVEL PHOTOCHEMISTRY OF A STERICALLY CROWDED MONOBENZOBARRELENE DERIVATIVE}, journal = {Tetrahedron Letters}, volume = {34}, number = {1}, year = {1993}, note = {ISI Document Delivery No.: KE371Times Cited: 6Cited Reference Count: 12}, month = {Jan}, pages = {31-34}, type = {Article}, abstract = {The solution phase photochemistry of the sterically congested tetramethylated benzobarrelene derivative 2b differs completely from that of its non-methylated counterpart, 2a. Based on molecular mechanics calculations, the factor that is suggested to be responsible for this difference is relief of the unfavorable methyl-methyl interactions present in 2b.}, keywords = {3-DICARBOXYLATE, 4-DIHYDRO-1, 4-ETHENONAPHTHALENE-2, DIMETHYL 1, SOLID-STATE, SUBSTITUTED DIBENZOBARRELENE}, isbn = {0040-4039}, url = {://A1993KE37100005}, author = {Jones, R. and Scheffer, J. R. and Trotter, J. and Yap, M.} }