摘要:

The high resolution photoelectron spectra for the following iodine-containing molecules have been measured: iodomethane, 1-iodoethane, 1-iodopropane, 1-iodobutane, 1-iodopentane, 1-iodohexane, 2-methyl-1-iodopropane, 3-methyl-1-iodobutane, 2-iodopropane, iodocyclopentane, iodocyclohexane, 2-methyl-2-iodopropane, trifluoroiodomethane, 2,2,2-trifluoro-1-iodoethane, pentafluoroiodoethane, 3,3,3,2,2,1,1-heptafluoro-1-iodopropane, iodobenzene, pentafluoroiodobenzene, vinyl iodide, allyl iodide. The spectra are discussed in terms of extended Hückel (EH) molecular orbital calculations and of the qualitative changes upon variation of the alkyl group.

ISSN:0008-4042    

DOI:10.1139/v74-190

出版商:NRC Research Press    

年代:1974

数据来源: NRC

摘要:

Substituted 9,10-dihydroanthracenes were synthesized by reducing the corresponding anthraquinone with a mixture of hydriodic acid, phosphorus, and iodine.

ISSN:0008-4042    

DOI:10.1139/v74-191

出版商:NRC Research Press    

年代:1974

数据来源: NRC

摘要:

Nitration of 2,3-dimethylbenzonitrile in acetic anhydride gives the adduct 2-cyano-3,4-dimethyl-4-nitro-1,4-dihydrophenyl acetate as well as the expected nitro substitution products. Similarly 3,4-dimethylbenzonitrile affords 2-cyano-4,5-dimethyl-4-nitro-1,4-dihydrophenyl acetate as well as the 3,4-dimethylnitrobenzonitriles. Thermolysis or decomposition in acetic acid of the adducts gives the original dimethylbenzonitrile and its 5-nitro derivative as the major products, the latter apparently being formed by an intramolecular 1,3-shift of the nitro group. Decomposition of the adducts under more strongly acidic conditions results in the elimination of nitrous acid and the formation of 2-cyano-3,4-dimethylphenyl acetate and 2-cyano-4,5-dimethylphenyl acetate, respectively. In acidified methanol the adducts undergo transesterification at the acetate function and 2-cyano-3,4-dimethyl-4-nitro-1,4-dihydrophenol and 2-cyano-4,5-dimethyl-4-nitro-1,4-dihydrophenol are obtained.

ISSN:0008-4042    

DOI:10.1139/v74-192

出版商:NRC Research Press    

年代:1974

数据来源: NRC

摘要:

Palladium(II) acetate in acetic acid in the absence of acetate ion exists as the trimeric species Pd3(OAc)6. The reaction of the trimer with NaOAc or LiOAc at 25° was not instantaneous. Spectral studies on fully equilibrated systems indicated the first equilibria involved transformation of trimer to dimerwithK32 = 7.77 × 104 M−5andK′32 = 1.76 × 102 M−5. The kinetics of the slow transformation of trimer to dimer was studied. The reaction has the rate expression: rate = [Pd3(OAc)6] (k + k′[MOAc]) (M = Li or Na). This rate expression is consistent with substitution processes suggesting the slow step of the reaction is the SN2 attack of solvent or acetate on a Pd(II)–acetate bond to break one of the acetate bridges.In the NaOAc system conversion of trimer to dimer was complete at 0.2 MNaOAc. Further addition of NaOAc caused the dimer to be converted to monomer.

ISSN:0008-4042    

DOI:10.1139/v74-193

出版商:NRC Research Press    

年代:1974

数据来源: NRC

摘要:

γ-Irradiation of 1-methyl-5-methylnitro-aminotetrazole1and 1-methyl-5-nitro-aminotetrazole2resulted in cleavage of the exocyclic N—N bond giving only one detectable radical (NO2•) in each case. The stability and motion of the NO2•radicals formed in these systems was studied. The NO2•radical obtained from compound1was immobile in the lattice while that obtained from compound2was rotating about they-axis. Irradiation of 1-methyl-5-methyl-nitroso-aminotetrazole3and 1-phenyl-5-nitroso-aminotetrazole4did not give a simple N—N bond cleavage and radicals which could not be fully identified were encountered. The radical obtained from compound3appeared to be a nitroxide radical and that obtained from compound4appeared to arise from electron capture by the nitrosamino moiety.

ISSN:0008-4042    

DOI:10.1139/v74-194

出版商:NRC Research Press    

年代:1974

数据来源: NRC

摘要:

Di-n-propyl disulfide is an electron, positive ion, and free radical scavenger in γ -irradiated liquid cyclohexane. The efficiency of electron scavenging is comparable with that of sulfurhexafluoride and the efficiency of H atom scavenging is comparable with that of ethylene. The expected product of cyclohexyl radical scavenging, namely cyclohexylpropyl sulfide, accounts for only about one quarter of these radicals which disappear. No other sulfur-containing products are found. In cyclohexane solutions containing two different disulfides or a disulfide and a thiol a rapid equilibration of the thiyl groups leads to their statistical distribution between the sulfur-containing species.

ISSN:0008-4042    

DOI:10.1139/v74-195

出版商:NRC Research Press    

年代:1974

数据来源: NRC

摘要:

The title compound containing a phenylthio group at C-3 and a methanesulfonate group at C-2 undergoes a quantitative transposition reaction in refluxing benzene to give the diequatorial isomer. In DMSO, a complex reaction takes place leading to elimination and oxidation at C-2. Oxidation of the title compound containing a phenylthio group at C-2, with acetic anhydride–DMSO gives the corresponding 3-uloside. With the isomeric 3-phenylthio derivative the enol acetate is formed. These results are rationalized based on mechanistic considerations.

ISSN:0008-4042    

DOI:10.1139/v74-196

出版商:NRC Research Press    

年代:1974

数据来源: NRC

摘要:

The condensation of 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide with sodio diethyl malonate led to crystalline diethyl 2-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl) malonate. The corresponding dibenzyl ester proved to be a versatile intermediate for the preparation of crystalline β-D-glucopyranosyl malonic acid and β-D-glucopyranosyl acetic acid derivatives. The anomeric configuration in theseC-glycosides was determined by a chemical correlation. With 2,3,4,6-tetra-O-acetyl- β-D-glucopyranosyl chloride and sodio diethyl malonate, the major product was a 1,2-O-ketal derivative resulting from an attack of the carbanion on the 1,2-acetoxonium ion. The condensation of 2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl bromide with sodio diethyl malonate was conducted with, and without added bromide ion and the mechanistic implications of the results are discussed.C-Glycosides were also prepared in theD-mannofuranose series and their transformation into theD-lyxofuranose series (anomeric mixture) is described. The utility of n.m.r. shift reagents, and an apparent differential complexation by Eu(DPM)3and Eu(FOD)3-d27is demonstrated.

ISSN:0008-4042    

DOI:10.1139/v74-197

出版商:NRC Research Press    

年代:1974

数据来源: NRC

摘要:

The condensation ofD-ribofuranosyl halides containing participating (benzoate) and non-participating (benzyl) substituents, with sodio dialkyl malonates and sodio triethyl 1,1,2-ethanetricarboxylate is described. In the presence of participating groups at C-2, the major and sometimes exclusive products were the 1,2-ketal derivatives. Both α- and β-anomericD-ribofuranosyl malonates were formed in the non-participating series. The possibility of epimerization (anomerization) was experimentally demonstrated.Similar results were obtained with the more highly functionalized tricarbethoxy carbanion. For the participating series however, 20% ofC-glycoside was obtained. Condensations with sodio diethyl malonate were also done in theD-arabinoseries (O-benzyl protecting group) and the anomericC-glycosyl compounds were isolated and characterized. The mechanistic aspects of these condensations are discussed.

ISSN:0008-4042    

DOI:10.1139/v74-198

出版商:NRC Research Press    

年代:1974

数据来源: NRC

摘要:

Wittig condensation of indole-1-(p-toluenesulfonyl)-3-methyltriphenylphosphonium iodide (8) with aromatic and heterocyclic aldehydes gives good yields of the 3-(2-aryl)-vinylindole derivatives9a–g(Scheme 1). Compounds11aand11bare obtained similarly starting with the known indole-1-methyl-3-methyltriphenylphosphonium salt10and pyridine-3- and -4-aldehydes. An alternate Perkin-type condensation route provides the trisubstituted 3-vinylindoles15aand15b(Scheme 2) which cannot be synthesized by the Wittig route.Compounds9aand9b;9eand11b;13,15a, and15b; as well as the previously known12a-cundergo photocyclodehydrogenation to give benzo- and pyridocarbazole derivatives16aand16b;18aand19a,18band19b;17a,17b, and17c; and16c–e, respectively in fair to good yields (Scheme 3). Compounds9d,9f, and11afail to photocyclize. The reasons for these failures are briefly explored and discussed.

ISSN:0008-4042    

DOI:10.1139/v74-199

出版商:NRC Research Press    

年代:1974

数据来源: NRC