Ring closure reactionsRing closure reactions O 0130 N-Bridgehead Heterocyclic Compounds Thenoly-Substituted. Part 2. Azaindolizines. -Quaternary salts of diazines, such as (I) and (IV) react with activated acetylenic compounds (II) in the presence of an epoxide to give the corresponding anellated products (III) and (V), respectively. -(GEORGESCU, E. I.; GEORGESCU, F.; ROIBU, C.; IUHAS, P. C.; DRAGHICI, C. C.; CAPROIU, M. T.; Rev. Roum. Chim. 47 (2002) 8-9, 885-891; S.C. OLTCHIM Res. Cent., RO-1000 Ramnicu-Valcea, Rom.; Eng.) -M. Paetzel 36-038

For the first time, new benzo[f]pyrrolo[1,2-a]quinoline derivatives, structurally analogous to the steroid skeleton, were obtained in a simple way by 1,3-dipolar cycloaddition reactions of benzo[f]quinolinium-1-methylides, generated in situ from the corresponding quaternary salts, with electron-deficient alkynes.

Ring closure reactions O 0130 One-Pot Synthesis of New Imidazo[1,2-a]pyridine and Imidazo[1,2-a]pyrimidine Derivatives. -The new title heterocycles (IV) are easily obtained by a two-step one-pot procedure. -(GEORGESCU*, F.; GEORGESCU, E.; DRAGHICI, C.; IUHAS, P. C.; FILIP, P. I.; Rev. Roum. Chim. 50 (2005) 5, 349-352; S.C. OLTCHIM Res. Cent., RO-1000 Ramnicu-Valcea, Rom.; Eng.) -H. Haber 12-043

Cycloaddition reactions Cycloaddition reactions O 0070Regiochemistry of the 1,3-Dipolar Cycloaddition of Some N-Heterocyclic Cycloimmonium Ylides to Unsymmetrical Alkynes. -In continuation of an earlier study the regiochemistry of such a reaction with various unsymmetrical substituted alkynes is investigated. -(IUHAS, P. C.; GEORGESCU, F.; GEORGESCU, E.; DRAGHICI, C.; CAPROIU, M. T.; Rev. Roum. Chim. 47 (2002) 3-4, 333-338; S.C. OLTCHIM Res. Cent., RO-1000 Ramnicu-Valcea, Rom.; Eng.) -K. Schneider 30-053

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