Substituted Ethers

Saponification of alkyl peroxyesters yields alkyl hydroperoxides and carboxylic acids or their alkali metal salts. a-Ether-substituted peroxides can be hydrolyzed to the unsubstituted alkyl hydroperoxides, eg, tert-huty hydroperoxide from tert-huty 2-oxacyclohexyl peroxide [28627-46-5] (62) ... 

Accordingly, iV-phenyl-substituted isothiazolium salts bearing a benzo crown ether substituent were employed in this synthetic protocol and led to the synthesis of various crown ether-substituted 6aA4-thia-l,6-diazapentalenes 201... 

Sample Mw Mw/Mn Degree of hydrolysis Degree of ether substitution/monomer... 

The first alkyl side-chain ether-substituted polysilane to be prepared was 40, with a single oxygen atom in one of the side chains. The polymer is soluble in alcohols, including methanol, in addition to common non-polar organic solvents.144 145... 

The oxygen atom not only imparts polarity, but also flexibility, as was discussed156 for two early ether-substituted polysilanes, poly(5-oxaoctyl- -propylsilylene) and poly(5-oxaoctyl- -hexylsilylene). To investigate this further, Yuan and West, using the same standard Wurtz procedure, prepared a series of poly(oxaoctylmethylsilylene) isomers and their symmetrical counterparts, in which the position of the oxygen atom was varied in side-chain positions 5, 6, and 7.157... 

Pond SJK, Tsutsumi O, Rumi M et al (2004) Metal-ion sensing lluorophores with large two-photon absorption cross sections aza-crown ether substituted donor-acceptor-donor distyryl benzenes. J Am Chem Soc 126 9291-9306... 

A third mechanistically distinct [3 -1- 2] cycloaddition between vinyl ethers and vinyl-carbenoids was discovered and reported in 2001 [26]. This reaction is remarkable because when Rh2(S-DOSP)4 is used as the catalyst, the cis-cyclopentenes 142 are formed in up to 99% enantiomeric excess. The reaction occurs between vinylcarbenoids unsubstituted or alkyl-substituted at the vinyl terminus and vinyl ethers substituted with an aryl or vinyl group. Some illustrative examples are shown in Tab. 14.12. The reaction is considered to be a concerted process, which would be consistent with the highly stereoselective nature of the reaction [26]. Contrary to the [3-1-2] cycloaddition derived by means of vinylogous carbenoid reactivity, this latest [3 -1- 2] cycloaddition is not influenced by solvent effects. Due to steric demands on the carbenoid, the [3-1-2] cycloaddi-tion only occurs with cis-vinyl ethers. 

Triazole melts at 120-121 °C and boils at 260 °C. It has a density of 1.132 and a specific conductivity of about 10 0 cm , of the same order as imidazole. Triazole dissolves readily in water and ethanol but is only slightly soluble in ether. Substitution on N(l) usually lowers the melting point this effect is usually much smaller for substitution at N(4), although 4-aminotriazole has a melting point of 84-86°C. 3-Aminotriazole has a melting point of 159°C and the 3-thiol derivative of 221-... 

Levesque 1, Leclerc M. lonochromic effects in regioiegular ether-substituted pol3dhiophenes. J Chem Soc Chem Commun 1995 2293-2294. 

Frank Burnett Dains, 1869-1948. Lecture assistant to Dr. W. O. Atwater at Wesleyan University, Middletown, Connecticut, and later assistant professor at Northwestern University and professor at Washburn College in Topeka, Kansas. From 1911 until tire time of bis retirement in 1942 he was in charge of the department of organic chemistry at the University of Kansas, where he made notable contributions to the chemistry of the aldehydes, urea ethers, substituted ureas, thiazoles, imidazoles, and pyrazoles, and was an enthusiastic collector of books, portraits, and other memorabilia connected with the history of chemistry. He was a charter member of the Chicago Section of the American Chemical Society and served as Councilor of the Society, as Chairman of the Divisions of Organic Chemistry and History of Chemistry, and as contributing editor and abstractor for the Journal of Chemical Education. See also ref. (166). 

Crown-ether-substituted ligands were first investigated by Okano et al. (structure 8), who prepared arylphosphanes with these groups (48). 

A typical 31P NMR spectrum consisted of a sharp, singlet resonance at -8 ppm, presumably a consequence of the similar environment at the trifluoroethoxy and ethoxy-ether substituted phosphorus atoms in the mixed-substituent system. In addition, the singlet resonance indicated a high degree of chlorine replacement. This was supported by the elemental microanalysis data. 

Griiner, B., Plesek, J., Baca, J. et al. 2002. Crown ether substituted cobalt bis(dicarbollide) ions as selective extraction agents for removal of Cs + and Sr2 + from nuclear waste. New J. Chem. 26 (7) 867-875. 

Fig. 10 Proposed structure for the cation-induced dimer of crown ether substituted metalloph-thalocyanines. Solid circles indicate cations such as K+ and Ca2 1 (reproduced from Kobayashi N, Lever ABP (1987) J Am Chem Soc 109 7433 with permission from the American Chemical Society)...

Cation-induced supramolecular formation of crown ether substituted phthalocya-nines can also be regarded as due to host-guest interactions. Fig. 10 shows the proposed structure for the K+- and Ca2+-induced dimer of metallophthalocya-nines fused with four 15-crown-5 units, which serves as a typical example. The formation of these cofacial dimers has been found to go through a two-step three-stage process. The earlier works have been briefly reviewed [93, 94], Recently, Jiang et al. have prepared a series of copper(II) phthalocyanines fused with one to four 15-crown-5 unit(s) [CuPc(15-C-5) ] (n = 1 1) by heating a solution of the double-decker complexes Eu(Pc)[Pc(15-C-5) ] (n = 1-4) with Cu(OAc)2 in... 

Figure 6. Enol ether substituted amino acid analogues of methionine which are inhibitors of ethylene production in plants...

These enol ether-substituted amino acids are natural products isolated from the fermentation broths of Rhizobium japonicum (rhizobitoxine) (31), Pseudomonas aeruginosa (methoxy analogue) (33) and a species of Streptomvces (ethoxy analogue) (34). 

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