3726-88-3Relevant academic research and scientific papers
Cyclobutene Photochemistry. The Photochemistry of cis- and trans-Bicyclonon-8-ene
Leigh, William J.,Zheng, Kangcheng,Clark, K. Brady
, p. 1574 - 1580 (1991)
Direct photolysis of cis- and trans-bicyclonon-8-ene in hydrocarbon solution with monochromatic far-UV (185-214 nm) light sources affords cis,cis- and cis,trans-1,3-cyclononadiene via formal electrocyclic ring opening, cycloheptene (and acetylene) via formal (?2s + ?2s) cycloreversion, and minor amounts of molecular rearrangement products.Product quantum yields have been determined for the 185-nm photolysis.The two isomers lead to similar distributions of the isomeric 1,3-cyclononadienes, with similar quantum yields at 185 nm; the diene mixtures are in bothcases weighted in favor of the less thermodynamically stable cis,trans-isomer.The product distributions vary only slightly with excitation wavelength over the 185-214-nm range.Quantum yields for direct photoisomerization of cis,cis- and cis,trans-1,3-cyclononadiene have also been determined.Two mechanisms are considered to explain the nonstereospecificity associated with the ring-opening process: a nonconcerted pathway involving initial cyclobutene bond homolysis and subsequent relaxation of common biradical intermediates, and a pericyclic pathway involving adiabatic, disrotatory ring opening to yield dienes in the first excited singlet state.While the results do not allow a definitive distinction between the two mechanisms, the nonconcerted pathway is suggested to be the more reasonable on the basis of the photobehavior of other cyclobutene derivatives that have been studied.The quantum yield of cycloreversion product is ca. 4 times higher from the cis isomer compared to that from the trans isomer, due to the stereochemical requirements of the process.
Deamination Reactions, 37. Decomposition of Bicyclononane- and Bicyclonon-2-ene-9-diazonium Ions
Kirmse, Wolfgang,Hellwig, Georg
, p. 2744 - 2754 (2007/10/02)
Bicyclononane-exo-9-diazonium ions (9) have been generated from the corresponding nitrosourea (8) and base.In weakly alkaline solution (E)-3-methoxycyclononene (11) was formed by disrotatory ring opening of (9).In the presence of sodium methoxide 1,2-cyclononadiene (13) and exo-9-methoxybicyclononane (15) were additional products, presumably arising via carbene 12.Bicyclonon-2-ene-exo-9-diazonium ions (21) decomposed without participation of the double bond to give the (Z,E)-methoxycyclononadienes 22 and 23.The 21-derived carbene 29 afforded the bicyclic ether 30 and the elusive 1,2,4-cyclononatriene (32).In contrast to its lower homologs, 29 did not undergo a carbene-carbene rearrangement (29 -> 31).
