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Spiro Compounds (spiro + compound)
Selected AbstractsSynthesis and Structure Elucidation of New Spiro Compounds with Per(poly)fluoroalkyl GroupCHINESE JOURNAL OF CHEMISTRY, Issue 7 2006Zhi-Jian Shi Abstract A series of spiro compounds have been synthesized via several steps. The structure of these compounds were confirmed by 1H NMR, 13C NMR, IR, MS spectra and X-ray diffraction analysis. The possible mechanism to form these products was also proposed. [source] Photochromic Properties of a Spirooxazine and a Spiropyran in Alcoholic Solutions of Zirconium and Aluminium Alkoxides: Influence of the Ethyl Acetoacetate Chelating Agent on the Optical PropertiesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 2 2003Aurélie Lafuma Abstract The photochromism of two spiro compounds, a spiropyran and a spirooxazine, dissolved in alcoholic solutions of metal alkoxides M(OR)n (M = Zr, Al) has been studied. In the case of the aluminium alkoxide Al(OsBu)3, special photochromic behaviour is observed characteristic of complexation between the coloured form of the dyes and the aluminium. This chemical interaction induces a considerable shift in the absorption spectra and a significant retardation rate in the dark. Addition of ethyl acetoacetate, a bidentate chelate of aluminium, leads to the disappearance of this particular photochromic behaviour. (© Wiley-VCH Verlag GmbH & Co KGaA, 69451 Weinheim, Germany, 2003) [source] Chemistry and heterocyclization of dithiobiurea and thioureidoalkylthioureaJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2010Alaa A. Hassan This review summarizes published data on the behavior and reactions of dithiobiurea and thioureidoalkylthiourea derivatives, which lead to the formation of heterocyclic systems, including methods of preparation in addition to synthesis of imidazolidine, thiazole, thioazolidine, triazolidine, thiadiazine, and spiro compounds. J. Heterocyclic Chem., (2010). [source] Synthesis and reactivity of spiro[1,3,4-thiadiazoline-2,4,-thioflavans] and analoguesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2009László Somogyi Racemic thioflavanone (thio)acylhydrazones undergo transformation into racemic 3-acetylspiro[1,3,4-oxa(thia)-diazoline-2,4,-thioflavans] with trans O(1) or S(1) and Ph(2,eq) under acetylating conditions. Conjugation between the ethylenic bond and sp2 C(4) in thioflavones encumber both the formation of (thio)acylhydrazones and their subsequent spirocyclization. On the other hand, subsequent dehydrogenation of the thiopyran moiety of spiro compounds results in formation of sp2 C(4) and simultaneous degradation of the spirodiazoline ring. J. Heterocyclic Chem., 46, 399 (2009). [source] Cycloaddition reaction of schiff bases with ketenes generated by pyrolysis of 2-aryl-substituted 1,5,7-trioxaspiro[2.5]octane-4,8-dionesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 1 2006Takashi Tsuno The ,-oxo ketenes 6 which are generated by the pyrolysis of the 2-aryl-substituted 1,5,7-trioxaspiro[2.5]octane-4,8-diones 1, were reacted with Schiff bases 2 to give spiro compounds constructed between the ,-lactam and 1,3-dioxolan-4-one; i.e., the 2,3,6-triaryl-2-aza-5,7-dioxaspiro[3.4]octane-1,8-diones 3 and 4. Hydrogenation of the mixture of 3a and 4a in the presence of catalytic amount of Pd-C produced the trans -2-benzyloxy-1,4-diphenyl-,-lactam-3-carboxylic acid 9. [source] Isolation of methyl (RS)-1- tert -butoxycarbonyl-3-cyanomethyl-1,2-dihydro-2-oxo-5H -pyrrole-5-carboxylate, the key-intermediate in base-catalyzed formation of racemic products by 1,3-dipolar cycloadditions to methyl (S)-1- tert -butoxycarbonyl-3-[(E)-cyanomethylidene]-2-pyrrolidinone-5-carboxylateJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2002Marko Cycloadditions of various 1,3-dipoles to methyl (S)-1- tert -butoxycarbonyl-3-[(E)-cyanomethylidene]-2-pyrrolidinone-5-carboxylate (9) were studied. Reactions of 9 with diazomethane (10) and 2,4,6-trimethoxy-benzonitrile oxide (11), carried out under neutral conditions, gave the corresponding optically active spiro compounds 16-18 with low diastereoselectivity (20-30% diastereomeric excess). On the other hand, reactions of 9 with nitrile oxide 11 and nitrile imines 14, 15, carried out in the presence of a base, afforded racemic pyrazolo and isoxazolo fused 2-pyrrolidinones 21-23 in 82-86% diastereomeric excess. Optically active dipolarophile 9 was isomerized in the presence of basic alumina to give methyl (RS)-1- tert -butoxy-carbonyl-3-cyanomethyl-1,2-dihydro-2-oxo-5H -pyrrole-5-carboxylate (19). Treatment of the racemic dipolarophile 19 with dipoles 11 and 14, afforded fused 2-pyrrolidinones 23 and 21. These observations support compound 19 as the key-intermediate in the formation of racemic cycloadducts 21- 23. [source] Synthesis and photochromism of photochromic spiro compounds having a reactive pendant groupJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 1 2002Peng Zhang The photochromic spiropyrans and spirooxazines having a reactive pendant group, including carboxyl, halide, succinimidyl ester and isothiocyanate, were synthesized. Their photochromic behaviors in solution and solid state were studied. [source] Novel photochromic spiro compounds based on thieno[3,2- b]pyrrolesJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 11 2007Mikhail M. Krayushkin Abstract Previously unknown spiro compounds of thienopyrroline series were synthesized by a convenient method starting from easily accessible 3-hydroxythiophene derivatives. The photochromic properties of spiro compounds of thienopyrroline series were studied. Copyright © 2007 John Wiley & Sons, Ltd. [source] ChemInform Abstract: Regioselective Synthesis of Highly Functionalized 3-Spiropyrrolidine/Pyrrolizidine Oxindoles and Acenaphthenones via One-Pot Four-Component [3 + 2] Cycloaddition.CHEMINFORM, Issue 42 2010Kai Zhao Abstract Novel dipolarophiles, prepared in situ by Knoevenagel condensation of cyanoacetylindole (II) and aldehydes, undergo 1,3-dipolar cycloaddition with azomethine ylides derived from diketones and amino acids to yield highly functionalized spiro compounds. [source] Synthesis and Structure Elucidation of New Spiro Compounds with Per(poly)fluoroalkyl GroupCHINESE JOURNAL OF CHEMISTRY, Issue 7 2006Zhi-Jian Shi Abstract A series of spiro compounds have been synthesized via several steps. The structure of these compounds were confirmed by 1H NMR, 13C NMR, IR, MS spectra and X-ray diffraction analysis. The possible mechanism to form these products was also proposed. [source] | ||||||||||