nichtkonzertierte [2 + 2]-Cycloaddition von 1H-1,2-Diazepinen an Ketene hergestellt. Sie bilden eineneueKlassevonbicyclischenβ-Lactamen die strukturell den Cephalosporinantibiotika etwas ähneln. Diese Addukte besitzen jedoch keine saure Gruppe in α-Stellung zum Brückenkopfstickstoffatom; auch war keine bakteriostatische Wirkung zu erwarten. Ausgehend von monosubstituierten Ketenen und 1,2-Diazepinen
Reactions of 1H-1,2- and 1H-1,3-diazepines with dimethyl acetylenedicarboxylate
作者:Jyoji Kurita、Naoki Kakusawa、Takashi Tsuchiya
DOI:10.1039/c39870001880
日期:——
The title reactions yield the 3a, 7a-dihydropyrrolo[3,2-b]pyridines (2) and 3a,7a-dihydroindazoles (9), respectively, probably via the diazonine intermediates (4) and (8) derived from the initially formed [2 + 2]π cycloadducts; the indazoles (9) further react with the reagent to give the dimethyl phthalates (6) and the pyrazoles (7)via the [4 + 2]π cycloadducts (10).
标题反应可能分别通过最初形成的重氮基中间体(4)和(8)生成3a,7a-二氢吡咯并[3,2- b ]吡啶(2)和3a,7a-二氢吲唑(9)。[2 + 2]π个环加合物;的吲唑(9)还与所述试剂反应,得到二甲基邻苯二甲酸酯(6)和吡唑(7)经由所述[4 + 2]πcycloadducts(10)。
Stereospecific Synthesis of 2-Oxazinyl-4-oxoazetidinecarbamates Starting from a 1,2-Diazepine. A new type of intramolecular transbenzoylation
Azeitidinodiazepines 4b and 4c react with acylnitroso dienophiles 5a–c, specifically from their convexe α-side, but in a non-regiospecific way, leading thereby stereospecifically to the expected adducts 6a–d and 7a–d. The three-dimensional structures of 6a and 7a were determined by X-ray analyses which corroborated their NMR data. OsO4cis-glycolization occurred in good yield with the inverse adducts
Cycloaddition reactions of 1,2-diazepines with nitrile oxides. synthesis of 1,2,9-triaza-8-oxabicyclo-[5.3.0]-3,5,9-decatriene derivatives
作者:Jacques Streith、Gérard Wolff、Hans Fritz
DOI:10.1016/0040-4020(77)84084-2
日期:1977.1
A new heterocyclic system, 1,2,9-triaza-8-oxabicyclo-[5.3.0]-3,5,9-decatriene 4, has been synthesized by regiospecific 1,3-dipolar cycloaddition of nitrile oxides to the imine double bond of 1,2-diazepines. Bis-adduct 5a is obtained in only trace amounts showing that the imine double bond is more reactive than the Δ4-olefinic bond.
The photo-sensitized oxygenation of 1, 2-diazepines (1 and 12) and azepine (17) results in the formation of the corresponding relatively stable epidioxides (2, 13, and 18). The dioxides (2) react with potassium hydroxide to give the epoxy-ketones (10) and with methanol to give the solvent adducts (11), probably via the intermediates (8 and 9). Treatment of 13 with alumina gives the hydroxy-epoxide (15), which is converted to the epoxy-diazepinone (16) by an alkali treatment. However, a similar treatment of 18 with bases gives only N-ethoxycarbonylaniline (19) and does not give any other characterized products.