. LOCK. Can. J. Chem. 60, 1657Chem. 60, (1982.Irradiation of 2-cyanobicyclo[2.2. Ilhept-2-ene (2-cyanonorbornene, 4) in hexane, with the full arc of a mercury vapour lamp, gives the rearrangement products 1-cyanobicyclo[4.1 .O]hept-2-ene 5 and 7-cyanotricyclo[4. l.0.03.7]heptane 6 in the ratio 20: 1. These products were separated by preparative vpc. The structure of the major product 5 was determined by single crystal X-ray analysis. Reduction of 5 with lithium aluminum hydride gave the corresponding primary amine, which was converted to the p-bromobenzenesulfonamide 9, mp 150-15l0C, which gave single crystals from ethanol-water. The crystal and molecular structures are described. The minor product 6 was hydrogenated to give 7-cyanobicyclo[2.2. Ilheptane. Formation of 5 and 6 may involve concerted o,, + n,, and o,, + n,, processes respectively, which are photochemically allowed.

. Can. J. Chem. 65, 1128Chem. 65, (1987.Illumination of aqueous or organic solutions of nitrofurazone, 1, with fluorescent or tungsten light caused the appearance of two new compounds, 2 and 3. Compound 2, which eluted just before nitrofurazone on a reverse phase hplc column, had a mass spectrum identical to that of 1 and converted back to 1 at a rate proportional to the temperature and the polarity of the solvent when allowed to sit in the dark. High resolution proton nmr spectroscopy provided conclusive evidence that compound 2 is the syr~ isomer of 1. Compound 3 had a retention time, ultraviolet spectrum, and mass spectrum that were indistinguishable from those of synthetic 5-nitrofuraldehyde azine. The toxicity of 3 to E . coli was determined to be the same as 1 while its mutagenicity was over 10-fold lower. No detectable cross-links were formed in the DNA of E. coli in the presence of compound 3. Thus, it is unlikely that the relatively small amounts of the azine 3 formed have much influence on the antibacterial potency or mutagenicity of nitrofurazone solutions. However, these results do confirm the desirability of conducting experiments with these agents in the dark or under yellow light. Photochemical formation of syrl isomers was also observed with two other Schiff's base nitrofuran derivatives, nitrofurantoin and furazolidone. L'irradiation de solutions aqueuses ou organiques de nitrofurazone (1) par de la lumitre fluorescente ou au tungsttne conduit B l'apparition des deux nouveaux composts, 2 et 3. Le spectre de masse du composk 2, qui est klut juste avant la nitrofurazone par clhp en phase inverse, est identique B celui du compost 1 et, lorsqu'on le laisse reposk dans un solvant a I'abri de la lumitre, il se retransforme dans le compost 1 B une vitesse qui est proportionnelle a la temptrature et a la polaritt du solvant. La rmn ' H B haute rksolution a permis de dtmontrer sans ambigui'tt que le composk 2 est I'isomere syn du compost 1. Les temps de retention et les spectres de masse et ultraviolet du compost 3 ne peuvent ttre diffkrencits de ceux de l'azine synthktique du nitro-5 furaldthyde. On a dttermint que la toxicitt du compost 3 pour 1'E. coli est la mime que celle du compost 1 et que sa mutagtnicitt est dix fois moindre. On n'a pas pu dttecter de rkticulation de I'ADN du E. coli en prksence du compost 3. I1 semble donc peu probable que les petites quantitts de l'azine 3 qui se foment puissent influencer le pouvoir antibactkrien ou la mutaginicitt de solutions de nitrofurazone. Toutefois, nos resultats confirment qu'il est dksirable d'effectuer, avec ces agents, des exptriences B I'abri de la lumitre ou en prtsence de lumikre jaune. On a aussi observt la formation photochimique des isomkres syn avec deux autres bases de Schiff dtrivtes du nitrofuranne, soit la nitrofuranto'ine et la furazolidone.[Traduit par la revue]

Das Nitril (I) lagert sich bei Bestrahlung (450 W‐Hanovia) zum Bicyclus (II), daneben auch zum Tricyclus (III) um.