Carbonylation of acetylenic compounds. 1. Carbonylation of tertiary acetylenic alcohols

Conclusions Carbonylation of acetylenic alcohols in the presence of Pd-black and cobalt carbonyl leads to derivatives of alkylidenesuccinic acids in yield of 50%.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 603–607, March, 1980.     

Dihedral angle restriction within a peptide-based tertiary alcohol kinetic resolution catalyst

Kinetic resolution of several tertiary alcohols has been evaluated with a peptide-based catalyst that was designed to probe the role of dihedral angle restrictions for certain bonds within the catalyst. In particular, the nucleophilic residue (π-Me)-His has been replaced with the (β-Me)-(π-Me)-His. A synthesis of the key residue is presented, along with characterization data that suggests the substituent exerts a substantial ground state conformational effect. In addition, kinetic resolution data indicate that the H- to Me-substitution confers enhanced stereoselectivity in several tertiary alcohol resolutions.     

Some transformations of acetylenic alcohol epoxides

It is shown that the hydration of acetylenic alcohol epoxides containing an epoxide ring in the position relative to the triple bond in the presence of sulfuric acid leads to the formation of acetylenic triols: 6-methyl-4-heptyne-1,2,6-, 7-methyl-5-octyne-2,3,7-, 2,7-dimethyl-5-octyne-2,3,7-, and 2,3,7-trimethyl-5-octyne-2,3,7-triols. It was established that the hydration process is hampered as the number of alkyl substituents attached to the epoxide ring increases. The triols were subjected to intramolecular cyclization under the influence of mercuric chloride to the corresponding chloromercurated derivatives of furan: 2-(1-chloromercuri-2-methyl-1-propenyl) and 5-methyi-2-(1-chloromercuri-2-methyl-1-propenyl)furans. The IR and PMR spectral data are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1164–1167, September, 1977.     

Efficient resolution of 2,2′-dihydroxy-1,1′-binaphthalene-4,4′- and 6,6′-dicarboxylic acid by complexation with cinchonidine and brucine

2,2′-Dihydroxy-1,1′-binaphthalene-4,4′- and 6,6′-dicarboxylic acid were resolved efficiently by complexation with cinchonidine and brucine, respectively. The absolute configurations of these compounds were determined by X-ray crystallographic analyses.     

Four new guaianolides and acetylenic alcohol from Saussurea katochaete collected in China

Four new guaianolides and an acetylenic alcohol were isolated from Saussurea katochaete (Asteraceae) collected in China. The structures were determined based on the spectroscopic data including the absolute configuration by application of advanced Mosher's method.     

A new cryptand: synthesis and complexation with paraquat

[formula: see text] Inspired by folded, nonpseudorotaxane complexes of bis(m-phenylene)-32-crown-10 systems, we synthesized a new bicyclic crown ether containing two 1,3,5-phenylene units linked by three tetra(ethyleneoxy) units. The new cryptand forms a "pseudorotaxane-like" inclusion complex with N,N'-dimethyl-4,4'-bipyridinium bis(hexafluorophosphate) with association constant Ka = 6.1 x 10(4) M-1, 100-fold greater than that of an analogous simple crown ether.     

一种提高双氢青蒿素电化学检测分辨率的新方法

采用电化学方法研究了阳离子表面活性剂对双氢青蒿素(DHA)在银电极表面伏安行为的影响,并探讨了其电极界面的电化学机理。随着阳离子表面活性剂十六烷基三甲基溴化铵(CTMAB)的加入,DHA的还原峰电位发生明显的变化。当CTMAB的浓度为1.0×10-5mol/L时,DHA的峰电位正移了102 mV,活化能降低,DHA的过氧键更容易断裂。当CTMAB的浓度继续增大至7.0×10-4mol/L,DHA的峰电位负移了108 mV,活化能增大,DHA的过氧键更稳定。同时,还研究了酸度、温度和不同结构的阳离子表面活性剂对DHA伏安行为的影响,并提出其作用机制,从而建立一种提高DHA电化学检测分辨率的新方法。     

An efficient optical resolution of nitrogen-centered chiral β-hydroxy-tetraalkylammonium salts via complexation with (R)-BINOL

The optical resolution of nitrogen-centered chiral β-hydroxy-tetraalkylammonium bromides is demonstrated by using chiral BINOL as a complexing agent. Determination of the enantiopurities and absolute configurations of the resolved N-chiral tetraalkylammonium salts are described.     

一种新的手性拆分方法-包结拆分

综述了手性包结拆分方法在拆分外消旋化合物中的应用,并讨论了包结拆分中的手性识别原理。     

A turbidimetric micromethod for analysis of tertiary butyl alcohol

Summary A rapid turbidimetric method for the analysis of very dilute aqueous solutions of tertiary butyl alcohol has been developed, using a mercuric sulphate/sulphuric acid reagent similar to the Denigés reagent. Concentrations as low as 1–6 mg/litre can be determined to within about 5% error.

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Zusammenfassung Eine schnelle turbidimetrische Methode zur Bestimmung sehr verdünnter, wäßriger Lösungen von tertiärem Butylalkohol wurde beschrieben. Sie beruht auf der Reaktion mit einer dem Reagens vonDenigés ähnlichen Quecksilber(II)-sulfat-Schwefelsäure-Lösung. Konzentrationen von 1 bis 6 mg/1 können mit einer Genauigkeit von etwa 5% bestimmt werden.

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Résumé L'auteur a mis au point une méthode turbidimétrique rapide pour l'analyse de solutions aqueuses très diluées d'alcool butylique tertiaire; à cette fin il emploie un réactif acide sulfurique-sulfate mercurique semblable à celui deDenigès. Dans ces conditions il est possible de déterminer des concentrations s'abaissant à 1–6 mg/litre avec une erreur inférieure à environ 5%.

     

A new cleavage strategy for ester linked polymer supports: generation of a tertiary alcohol library

The addition of different Grignard reagents to polymer bound esters resulting in the generation of a tertiary alcohol library with concomitant cleavage is described.     

A quantitative approach to optical resolution

Significant statistical relationships have been found between the parameters characterizing the results and circumstances of the resolutions of seventeen phenylglycine derivatives. The successful predictions given for the results of six independent resolutions prove the utility of these relationships.     

A new fullerene complexation ligand: N-pyridylfulleropyrrolidine

The subject of this paper is a new fullerene building block design with the potential for defined geometry and good electronic communication. The synthesis and characterization of a new pyridinofullerene ligand capable of forming axially symmetric complexes with metalloporphyrins is reported. X-ray structural and molecular modeling studies, (1)H NMR, UV-vis spectroscopy, electrochemistry studies, and fluorescence quenching data support the formation of a strong complex between the new ligand and the metal center of ZnTPP. On the basis of computational studies, the highest occupied molecular orbital (HOMO) of this ligand is significantly different from a model compound with insulating carbons between the pyridine and the fullerene. The N-pyridinium fulleropyrrolidine salts of the new ligand and model compound were also prepared and their spectral and electrochemical properties are reported.     

Acetylene derivatives Communication 191. Preparation of acids from tertiary acetylenic alcohols

Summary A method was developed for the conversion of tertiary acetylenic alcohols to unsaturated acids.