trans-azo linkages in eight-, nine-, and ten-membered cyclic azo compounds

✍ Scribed by C.G. Overberger; M.S. Chi; Donald G. Pucci; J.A. Barry

• Book ID: 104245448
• Publisher: Elsevier Science
• Year: 1972
• Tongue: French
• Weight: 197 KB
• Volume: 13
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)94367-9

✦ Synopsis

We wish to report the preparations of the first medium-sized cyclic aso compounds possessing trans-aso linkages, namely, trans-1,2-diaza-1-cyclooctene (A), trans-3,8-dimethyl-trans-1,2-diaza-1-cyclooctene (11, trans-l,Z-diaza-lcyclononene (2) and trans-1,2-diasa-1-cyclodecene (4). Irradiation of o&-1,2diasa-1-cyclooctene (2)' for 10 hrs resulted in a 60% conversion to its isomer a, which was purified by chromatography over Florisil. The photoisomerisation, 3 which was shown to be reversible by irradiation of pure& (Scheme I), can be followed by nmr. The a-methylene protons of 2 appear as a triplet at 5.80 T, whereas the a-methylene protons of J are magnetically nonequivalent, resulting in multiplets at 5.05 and 6.50~.