Ether compounds syntheses

Smith, Jason A., 431 Sn2+ compounds, 233 Sn4+ compounds, 232 SNAr reaction. See also Nucleophilic aromatic substitution reaction poly(arylene ether sulfone) synthesis via, 336-340... 

Another effective radical cascade strategy started from bromomethyldi-methylsilyl propargyl ethers. " The synthesis of functionalized cyclopenta-none 108 was achieved as a single diastereomer, starting from the reduction of bromoderivative 107 in the presence of (TMSlaSiH (Reaction 83). When different substituents are used in the skeleton, as in compound 109, a completely different reaction pattern resulted (Reaction 84). 

Problem In the synthesis of a chiral crown ether, compound (19) was needed. Suggest a synthesis for it. 

Allenyl ethers are useful key building blocks for the synthesis of a-methylene-y-butyrolactones [129, 130], The synthesis of the antileukemic botryodiplodin was accomplished with the crucial steps briefly presented in Scheme 8.56. Bromoallenyl ethers 225 were easily prepared by base-induced isomerization from the corresponding /3-bromoalkyl alkynyl ether compounds and then subjected to electrophilic bro-mination with NBS. The resulting acetals 226 were converted into 2-alkoxy-3-methy-lenetetrahydrofurans 227 by dehydrohalogenation of the alkenyl bromide unit to an alkyne and subsequent radical cyclization employing tributyltin hydride [130],... 

Unfortunately, these aza-ethers showed limited solubility in the polar solvents that are typically preferred in nonaqueous electrolytes, and the electrochemical stability window of the LiCl-based electrolytes is not sufficient at the 4.0 V operation range required by the current state-of-the-art cathode materials. They were also found to be unstable with LiPFe. Hence, the significance of these aza-ether compounds in practical applications is rather limited, although their synthesis successfully proved that the concept of the anion receptor is achievable by means of substituting an appropriate core atom with strong electron-withdrawing moieties. 

Glycol ethers, in organometallic compound synthesis, 2 88 Glycolysis... 

Allylboron compounds, synthesis, 9, 170-171 5-Allylboron compounds, cross-coupling reactions, 9, 212 Allylboronic esters, synthesis, 9, 194—195 Allyl boryl ethers, isomerization, 10, 88 Allylchlorodimethylsilanes, for carbonyl allylations,... 

The title compounds 135 have been synthesized176 in up to 85% yields by a facile 18F-for-19F exchange reaction (equation 87) carried out in DMSO or in wet acetonitrile. The [18F]fluoride ion has been prepared also as TBAF salt or as a polymer-bound species177. The possible uses of aryl ethers for synthesis of radiopharmaceuticals are under investigation176. 

A template synthesis using Group I metal ions has recently been developed (114) for producing crown ether compounds from substituted benzenes, furans, and thiophenes, e.g., the reactions of l,2-bis(bromo-ethyl)benzene with disodium or dipotassium glycolates produced... 

Metalatlon of 2-alkynyl and 1,2-alkadienyl tetrahydropyranyl ethers furane synthesis. /-Butyllithium metalates the lithium alkoxide 1 to afford the allenyllithium compound a quantitatively. This anion reacts with alkyl halides or CH3OH to afford 2. Another metalation-alkylation protonation sequence proceeds via b to afford 3. Hydrolysis of the latter intermediate affords furanes directly. The overall sequence can be performed in one pot from a propargyl tetrahydropyranyl ether, r-butyl-lithium, and an aldehyde. ... 

Padwa and coworkers applied the silver(I)-promoted alkylation of silyl enol ethers to synthesis of substituted furans [19]. For example, treatment of various trimethylsilyl enol ethers of cycloalkanones 44 and (F)-2,3-diiodo-l-(phenylsulfonyl)-l-propene (45) with 2 equiv. AgBF4 gives alkylated products 46 resulting from Sn2 displacement of the terminal iodide. These compounds 46 further cyclize with triethylamine to produce the 2-phenylsulfonylmethyl substituted furans 47 (Sch. 10) [19a]. 

The first total synthesis of ( )-lycoridine margetine (33), a member of the non-basic alkaloids which possess antimitotic activity has been achieved (Scheme 3). The homoallylic alcohol (26) served as a latent diene in a Diels-Alder reaction with ethyl acrylate to give a diastereomeric mixture of adducts which upon base equilibration and hydrolysis provided the tmns-acid (27). Modified Curtius reaction on (27) afforded the corresponding isocyanate which was cyclized to the lactam (28) in 89% yield by a new method using boron trifluoride etherate. Compound (28) was converted into an N-acetyl derivative which upon basic hydrolysis gave the acid (29). Treatment of (29) with NBS followed by reflux in pyridine solution gave the lactone... 

Synthesis and structural elucidation of novel uranyl crown-ether compounds isolated from nitric, hydrochloric, sulfuric, and acetic acids, R. D. Rogers, A. H. Bond, W. G. Hippie, A. N. Rollins and R. F. Henry, Inorg. Chem., 1991, 30, 2671. 

Acyloin condensations of esters conducted with TMS-Cl and sodium in toluene give 1,2-bis(trimethyl-silyloxy)alkenes. In general, the silylacyloin reaction provides higher yields than the conventional acyloin reaction and is particularly useful for the preparation of cyclic enol silyl ethers. " The synthesis of compound (47) serves as an illustration. 

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