Ethers di

GIvcol Ethers - Includes mono- and di- ethers of ethylene glycol, diethylene glycol, and triethylene glycol. 

The structure (342 R,R = Me or PhCH2) of the di- -ethers of perthiocyanic acid has been confirmed by Goerdeler and his co-workers.91 These compounds, which are the products of the alkylation of perthiocyanic acid (340) or its salts,144,147 were unequivocally synthesized (t) by the interaction of 3-alkyl(or aralkyl)thio-5-chloro-l,2,4-thiadiazoles (344 R = Me or PhCH2) with the appropriate thiols (R SH)91, and (ii) by alkylation of the monoethers (345 R = Me or... 

With new catalysts based on di-ether technology (5th generation catalyst, RK-Catalystand RH-Catalyst), wider melt-index ranged polymers can be produced (compare with those produced with 4th generation catalyst) due to the high hydrogen response of RK/RH-Catalyst. 

The product of Step 2 was also converted into the corresponding di-ether by reacting it with 2 equivalents of an alkyl halide with N,N-diisopropylamine dissolved in CH2CI2 and is described by the author. 

The glycols form well characterized esters and ethers in which one, or both, hydroxyl groups may be affected, thus yielding mixed compounds, i.e., alcohols and esters or ethers combined, also di-esters and di-ethers. 

Heliotropin, Piperonal.— Heliotropin receives its other name of piperonal from its relation to compounds occurring in pepper. In black pepper, Piperus nigra there is present an alkaloid known as piperine (p. 888). From this alkaloid an acid, piperic acid, is obtained. This acid is a methylene di-ether containing an alpha unsaturated side chain as in iso-eugenole, etc. On oxidation the side chain breaks at the double bond, as has been explained, and yields an aldehyde which is piperonal. 

Catalytic hydrogenation [494-9] and electrolytic reduction [500] of morphine affords dihydromorphine [xi], which can also be obtained by the demethylation of dihydrocodeine the optical antipode can be prepared in the sinomenine series from (4-)-dihydrocodeine [502-3] (see Chap. XXVI], Dihydromorphine can be esterified [504], converted into ethers [371, 504], heteroethers [446-8], and di-ethers [505], Dihydromorphine dimethyl ether is identical with tetrahydrothebaine [505-7] it can be demethylated to dihydromorphine [506-7],... 

Solvent petroleum ether/ethyl acetate (3 2)—3 spots top spot, Rf = 0.46, due to ethyl 4-hydroxybenzoate, next spot, R, = 0.33, due to mono-ether, and lowest spot, Rf = 0.20, due to di-ether. 

Alkyl-diols or alcohols may undergo etherification reactions over a solid acid catalyst. It has been demonstrated that simple diols may etherify either with mono-or di-substitution. In Scheme 12.3, if 1,6-hexanediol is used then a high conversion is obtained for the monomethylether (>60 %) this is thought to be due to the difference in polarity between the mono- and di-ether species [53]. 

Das Verfahren kann zur Preparation von En-diolethern dienen. Bei Einsatz unterschiedlicher Thiocarbonsaure-O-ester fallen in geringen Ausbeuten auch unsymmetrische En-diol-diether an. Die En-diol-di-ether liegen zunachstals Gemische aus cis- und trans-F orm vor. die bei langsamer Destination in die reinen rro/ts-Formen umgewandelt werden. 

Solubility op Magnesium Iodide Di Etherate (MgIj.2C4H,0) in... 

Two liquid phases appear near the melting point of the magnesium iodide di etherate. The lower may be considered as a solution of ether in di etherate, and the upper as a solution of the lower layer in ether. The critical temperature is 38.5°. 

A di-ether of an acetal of keto-v-erythro-pentalose, namely, 3,4-0-isopropylidene-l,5-di-0-trityl-fccto-D-erj/fhro-pentulose (78), has been... 

In the field of nucleophilic additions to arenechromium tricarbonyls [50], the chromium complex of phenyloxazohne adds various organohthium reagents re-gio- and enantioselectively in the presence of (-)-sparteine (or chiral 1,2-di-ethers). The hthium adduct thus formed has been trapped with propargyl bromide, leading to a frans-disubstituted cyclohexadiene of high ee [51] (Scheme 30). 

This deviation from linearity shows itself also in the solvation dynamics. Figure 4.3.7 shows the linear response functions and the non-equilibrium solvation function, C(t) and S(t), respectively, computed as before, for the di-ether H(CH20CH2)2CH3 solvent. Details of this simulations are given in Ref. 1 lb. If linear response was a valid approximation all the lines in Figure 4.3.7 The two lines for C(t) that correspond to q=0 and q=l, and the two lines for S(t) for the processes q=0—K =l and the process q=l—X =0, would coalesce. The marked differences between these lines shows that linear response theory fails forfliis system. 

Tetrahydrofuranyl ethers of thymidine and 2 -deoxycytidine have been prepared by acid-catalysed reaction of the nucleosides with 2,3 dihydrofuran mixtures of the 3 - and 5 -mono- and 3 5 -di-ethers were obtained. 3 -0-Tetra-hydrofuranyl-thymidine was also obtained by etherification of 5 -6>-palmitoyl thymidine followed by deacylation, and rat liver microsomes were found to convert the 3, 5 -diether selectively to the 5 -ether. The puramycin analogues (58) has been prepared from a 5 -blocked adenosine derivative. 

Reaction of activated (as dimesylate) diol 71 with ortho- meta- and para-nitrophenols afforded the corresponding di-ethers which were converted into diamines 72. Both amino-functions were coupled with the acid... 

About 130 years after the 1795 discovery of ethylene [2, 3], the lower olefins became important intermediates for manufacturing many industrial chemicals, including glycol, glycol mono- and di-esters, glycol mono- and di-ethers, glycol ether esters, polyethylene glycols, ethanolamines, and morpholine [2, 5]. 

---