| dc.contributor.author | McManus, Kimberly Ann. | en_US |
| dc.date.accessioned | 2014-10-21T12:38:53Z | |
| dc.date.available | 1992 | |
| dc.date.issued | 1992 | en_US |
| dc.identifier.other | AAINN76735 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55308 | |
| dc.description | Previous studies of the photo-NOCAS (photochemical nucleophile-olefin, combination aromatic substitution) reaction have focused upon monoalkenes, including prospective ring-opening alkenes. In this thesis, the study has been extended to conjugated dienes and unconjugated dienes (and their potential to undergo ring closure). | en_US |
| dc.description | The unconjugated dienes studied were 1,5-hexadiene (12), 2-methyl-1,5-hexadiene (13) and 2,5-dimethyl-1,5-hexadiene (14). These dienes were irradiated in the presence of 1,4-dicyanobenzene in acetonitrile-methanol (3:1) solution. The three dienes behaved quite differently. Diene 12 gave cycloaddition to 1,4-dicyanobenzene and dienes 13 and 14 each gave normal acyclic photo-NOCAS products. Addition of the co-donor, biphenyl (9), to the irradiation mixture was found to increase the efficiency of the photo-NOCAS reaction for the latter two dienes. Only for the case of 2,5-dimethyl-1,5-hexadiene with biphenyl present were cyclized products observed. Both cis- and trans-4-(4-cyanophenyl)-1-methoxy-1,4-dimethylcyclohexane (23 and 24) were formed. The mechanism and limitations of the reaction are discussed. | en_US |
| dc.description | The conjugated dienes studied were 1,3-butadiene (37), 2-methyl-1,3-butadiene (38), 2,3-dimethyl-1,3-butadiene (39) and 2,5-dimethyl-2,4-hexadiene (36). Dienes 37, 38 and 39 were irradiated in the presence of 1,4-dicyanobenzene and biphenyl in acetonitrile-methanol (3:1) solution. Both 1,2- and 1,4-addition products were formed in an approximate equimolar ratio (total yields range from 50-60%). However, irradiation of 2,5-dimethyl-2,4-hexadiene, 1 and 9 in acetonitrile-methanol (3:1) solution yielded 86% 1,4-addition products; trans-2-(4-cyanophenyl)-5-methoxy-2,5-dimethyl-3-hexene (35,82%) and trans-2-(4-cyanophenyl)-2,2,5-trimethyl-3-hexenenitrile (40, 4%). Irradiation of an acetonitrile solution containing 36 and 1 yielded 94% 40. The mechanism of this reaction is discussed. Also, a probable explanation of the regio- and stereoselectivity of the photo-NOCAS reaction involving these conjugated dienes is given. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1992. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Chemistry, Organic. | en_US |
| dc.title | Photochemical nucleophile-olefin, combination aromatic substitution (photo-NOCAS) reaction: Methanol, dienes, 1,4-dicyanobenzene. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
