1670
J. Org. Chem.
1988,53, 1670-1672
A 3-Azacyclopropanespiro-1J-dioxetane via Singlet Oxygenation of a Methyleneaziridine Takeshi Akasaka, Yuko Nomura, and Wataru Ando* D e p a r t m e n t of Chemistry, University of Tsukuba, Tsukuba, Ibaraki 305,J a p a n Received S e p t e m b e r 9, 1987
The f i t three-membered ring substituted spiro-l,2-dioxetane(2) has been synthesized and characterized through the singlet oxygenation of methyleneaziridine1. Thermodynamic properties of the decomposition of 2 are as follows: kzOOc= 11.5 s-'; E , = 18.3 kcal/mol; AH* = 17.9 kcal/mol; AS* = 7.5 eu. The chemical properties of this novel dioxetane are compared to those of dioxetanes 11 and 12, dioxetanimine 9, and dioxetanone 10. The synthesis of stable 1,2-dioxetanes has been abundantly documented and extensively utilized for the mechanistic exploration of chemienergized electronic excitation.' The considerably less stable dioxetanones (aperoxy lactones), which are an interesting class of highenergy compounds because of similarity to the postulated reaction intermediates in bioluminescence,'d@*2 produce electronic excitation through chemically initiated electron-exchange luminescence (CIEEL).3 The thermal stability of l,2-dioxetanes is affected by substituents on the dioxetane ring.4 Work on the synthesis and characterization of dioxetanimines through the singlet oxygena~ tion of ketene imines has only recently been r e p ~ r t e d . In the course of our search for new chemiluminescence systems: we have now synthesized and characterized 3-(Ntert-butyl-azacyclopropane)spiro-4-adamantane-spiro-1,2dioxetane 2 through the photooxygenation of l-tert-butyl-2-adamantylideneaziridine1 as the first three-membered ring substituted spiro-1,2-dioxetane. 1 was synthesized by treatment of 3 with an excess of n-butyllithium in tetrahydrofuran effecting dehydrobromination' as shown in Scheme I. Photooxygenation of 1 (0.4 M) for 1 h in deuteriochloroform at 15 "C with methylene blue (MB) as sensitizer using two 500-W tungsten-halogen lamps led to formation of adamantanone (6) quantitatively as an isolable product. That singlet oxygen is the oxidizing species was shown by the fact that 1 is stable under the reaction conditions in the absence of the sensitizer and light, and 1,4-diazabicyclooctane,a singlet oxygen quencher,s inhibited the reaction. Direct 'H (100 MHz) and '3c NMR (100 MHz) and IR analyses of the reaction mixture indicated the presence of a-lactam 7;Qsinglet proton resonances at (1) For reviews, see: (a) Adam, W. Adu. Heterocycl. Chem. 1979,21, 437. (b) Horn, K. A.; Koo, J.-Y.; Schmidt, S. P.; Schuster, G. B. Mol. Photochem. 1978,9, 1. (c) Adam, W.; Zinner, K. In Chemical and Biological Generation ojExcited States; Adam, W., Cilento,G., Eds.; Academic: New York, 1982; pp 153-190. (d) Adam, W. In The Chemistry of Peroxides; Patai, S., Ed.; Wiley: New York, 1983; pp 829-920. (e) Adam, W.; Yany, F. In Small Ring Heterocycles; H w n e r , A., Ed.; Wdey New York, 1985; Part 3, pp 351-430. (0Baumstark, A. I. In Singlet 0,; Frimer, A. A., Ed.; CRC: Boca Raton, FL, 1985; pp 1-36. (2) Shimomura, O., in ref IC, pp 249-277. (3) (a) Schmidt, S. P.; Schuster, G. B. J. Am. Chem. SOC.1978,100, Yany, F. J. Am. Chem. SOC.1978,100, 1966. (b) Adam, W.; Cueto, 0.; 2587. (4) Adam, W.; Paader, W. J. 4. Am. Chem. SOC.1985, 107, 410 and references cited therein. ( 5 ) (a) Ito, Y.; Matauura, T.; Kondo, H. J.Am. Chem. SOC.1979,101, 7105. (b) Adam, W.; De Lucchi, 0.;Quast, H.; Rectenwald, R.; Yany, F. Angew. Chem., Znt. Ed. Engl. 1979, 18, 788. (c) Ito, Y.; Yokoya, H.; Kyono, K.; Yamamura, S.; Yamada, Y.; Matsuura, T. J. Chem. Soc., Chem. Commun. 1980,898. (6) (a) Akasaka, T.; Sato, R.; Ando, W. J. Am. Chem. SOC.1985,107, 5539. (b) Ando, W.; Kabe, Y. J. Chem. SOC.,Chem. Commun. 1984,741. (7) (a) Wijnberg, J. B. P. A.; Wiering, P. G.; Steinberg, H. Synthesis 1981,901. Quast, H.; Jacob, R.; Peters, K.; Peters, E.-M.; von Schnering, H. G. Chem. Ber. 1984,117,840. (b) Sasaki, T.; Eguchi, S.; Hirako, Y. Tetrahedron Lett. 1976, 541. (8) Foote, C. S.; Peterson, E. R.; Lee, K.-W. J. Am. Chem. SOC.1972, 94. 1032.
5
6 1.27 (9 H) and 2.65 (2 H), 13Cresonance at 6 162.3,'O and a carbonyl band at 1850 a-Lactam 7 was not trapped by methan01;~however it was successfully converted to the corresponding oxaziridine 812(27% conversion yield) by oxidation with m-chloroperbenzoic acid (mCPBA) in the presence of sodium ~arb0nate.l~ Furthermore, 'H and '% NMR monitoring of the reaction mixture at low temperature (-74 "C) confirmed the presence of a thermally labile product (2), which exhibited 13C resonances at 6 86.8 and 94.3 consistent with the chemical shifts of dioxetane ring carbons.ls Warming up to -50 OC resulted in decrease of the dioxetane peaks (T1/2 = 20 min) and increase of the a-lactam signal.
ril N-r-Bu
0-0
2
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