摘要:

The radical-type diaddition of simple aliphatic and aromatic thiols, thiolacetic acid, dialkyldithiophosphoric (phosphorodithioic) acids, 2-mercaptoethanol, mercaptoacetic acid, 2-mercaptopropionic acid, and their esters to allene was studied. In general, such diadditions were found to be better than known metathetical reactions for the large-scale synthesis of trimethylene bis-sulfide compounds, the products of terminal diaddition. The various types of thiol compounds differ widely in their reactivity towards allene. A comparison of the data fort-butane- and benzene-thiol addition suggests that, in general, the amount of branched diadducts from monoadditions is directly proportional to the hydrogen-donor ability of the thiol, and that the amount of the allylic monoadduct formed is proportional to the stability of the thiyl radical.

ISSN:0008-4042    

DOI:10.1139/v67-196

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The substituent effects on the chemical shifts of the C9bridge protons in a series of 6-substituted benzonorbornenes and benzonorbornadienes, and on those of the C2protons in 5-substituted 2-indanols, were investigated. They were linearly correlated with the modified Hammett relationship τR − τH = ρ (σm + σp)/2. The ρ values obtained from theanti-C9protons in the bornenes and bornadienes were slightly but significantly larger than those from the correspondingsynprotons, whereas no significant difference was observed between the ρ values obtained fromsyn-9-benzonorbornenols and the indanols. The larger ρantivalues were explained in terms of a stereospecific electronic interaction between the π-electron system of the benzene ring and the orbital system of the bridge carbon. In addition, it was shown that the above modified Hammett relationship gives generally a good agreement with the substituent effects on the aliphatic constituents of benzocyclenes and analogous compounds.

ISSN:0008-4042    

DOI:10.1139/v67-197

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The reaction of alkylsulfenyl chlorides with 3,4-dihydro-2H-pyran, followed by treatment of the product with sodium methoxide, gave, highly stereoselectively,trans-3-alkylthio-2-methoxytetrahydropyrans. Purification by distillation under a vacuum at temperatures above 55° resulted in the elimination of methyl alcohol to produce 5-(alkylthio)-3,4-dihydro-2H-pyrans in a good yield. At lower temperatures, the more volatile homologues could be distilled undecomposed, but these had undergone thermal isomerization to a mixture ofcis- andtrans-3-alkylthio-2-methoxytetrahydropyrans. The conformational preference of these isomers is discussed.

ISSN:0008-4042    

DOI:10.1139/v67-198

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The spectral data, predominantly nuclear magnetic resonance spectra, of a number of carbonyl-bridged and related compounds have been examined. In most instances they confirm the structures arrived at by classical procedures, but in some instances revisions have been made.

ISSN:0008-4042    

DOI:10.1139/v67-199

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

TheGvalues for the formation of H2, H2S, alanine (CyH), and cystine ((CyS)2) in the60Co γ-radiolysis of 10−3and 10−2 Msolutions of cysteine (CySH) in 1Nperchloric acid at 23 °C have been determined. They are quantitatively consistent with the following reaction mechanism.The yields of H2and H2S have also been measured at 1 ± 1°C. If H atoms are assumed to be the only reducing species in 1Nperchloric acid,k1/k2was found to be 3.5 at 23 °C and 8 at 1 °C.

ISSN:0008-4042    

DOI:10.1139/v67-200

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The antibiotic caerulomycin is shown to be 4-methoxy-2,2′-dipyridyl-6-syn-aldoxime (I) by chemical and spectroscopic studies.

ISSN:0008-4042    

DOI:10.1139/v67-201

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

5-Aryl-1,2,4-dithiazole-3-thiones may be made by sulfurization ofN-aroyl-isothiocyanates, -thionocarbamates, or -dithiocarbamates. Attempts to produce 5-alkyl compounds failed, whereas an alternate cyclization of a reaction intermediate produced a 1,3-thiazine from cinnamoyl isothiocyanate. The mechanisms of the reactions are discussed briefly. The thiones readily form adducts with methyl iodide and reactive acetylenes. In the latter case, 1,3-dithiole derivatives are obtained.

ISSN:0008-4042    

DOI:10.1139/v67-202

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

It is shown that optically active methyl-α-naphthylphenylsilyldiphenylcarbinol and optically active methyl- α naphthylphenylsilylmethylphenylcarbinol undergo highly stereo-selective rearrangements to the isomeric silyl ethers. Both rearrangements involve retention of configuration at the asymmetric silicon center. The silylmethylphenylcarbinol is also shown to undergo retention of configuration with complete stereoselectivity at the asymmetric carbon center, regardless of the catalyst or solvent employed. The use of nuclear magnetic resonance for determining the proportions of the diastereomers is described, as are the syntheses of a number of asymmetric silicon compounds.

ISSN:0008-4042    

DOI:10.1139/v67-203

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

A description of the conditions which favor the formation of the acid chloride – dimethyl formamide complex is given. The utility of the complex is illustrated by its application to the synthesis of acyl azides and, in particular, by the selective formation of 3-bromopropionyl azide from the corresponding acid chloride. The complex also results from a carboxylic acid salt andN,N-dimethyl chloroformiminium chloride, and thus provides an alternative method of effecting the direct conversion of a carboxylic acid into the corresponding acid azide.

ISSN:0008-4042    

DOI:10.1139/v67-204

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

not available

ISSN:0008-4042    

DOI:10.1139/v67-205

出版商:NRC Research Press    

年代:1967

数据来源: NRC