By transetherification

Sulfolane has found utility as a solvent for the preparation of vinyl ethers of sucrose by transetherification with butyl vinyl ether ... 

The substrates for allyl vinyl Claisen rearrangements are conveniently obtained by transetherification of vinyl alkyl ethers with allylic alcohols. Typical examples of this rearrangement are represented in Scheme 2.155. The transformation of allyl vinyl ether 482 into aldehyde 483 illustrates the unique potential of the Claisen rearrangement as a method to prepare angularly substituted derivatives from readily available precursors such as 484, a goal hardly achievable by other routes. Products of this type are used as key intermediates in the syntheses of many natural compounds. ... 

The chiral alcohols are mainly employed as esters or enol ethers. Esters with carboxylic acids can be obtained by any convenient esterification technique. Dienol ethers were obtained by transetherification with the ethyl enol ether of a 1,3-diketone, followed by Wittig reaction8 silyldienol ethers were obtained by the method of Danishefsky11-12 and simple enol ethers by mercury-catalyzed transetherification13. Esters and enol ethers have been used as chiral dienophiles or dienes in diastereoselective Diels-Alder reactions (Section D. 1.6.1.1.1.1.). (R)-l-Phenylethanol [(R)-4] has been used for enantioselective protonation (Section C.) and the (S)-enantiomer as chiral leaving group in phenol ethers for the synthesis of binaphthols (Section B.2.) the phenol ethers are prepared as described for menthol in the preceding section. (S)-2-Octanol [(S)-2] has found applications in the synthesis of chiral allenes (Section B.I.). 

Many monoterpenes are desired fragrances in perfumery and flavors in food. They are produced on a larger scale from acetone (C3) and ethyne (acetylene C2) involving repetitive synthetic steps (Fig. 5). Initially, acetone is ethynylated by acetylene in the presence of a base (sodium hydroxide, amines with sodium carbonate) yielding 3-butyn-2-ol (C5) which is partially hydrogenated in the presence of deactivated catalysts (Lindlar catalysts) to 2-methyl-3-buten-2-ol. This can be converted to the key intermediate 6-methyl-5-hepten-2-one (Cg) via two pathways, either by transetherification with methylpropenylether and subsequent oxa-CoPE rearrangement, or by transesterification with methyl acetoacetate and subsequent Carroll decarboxylation. 

An alternative synthesis involves the transetherification of 3,4-dimethoxythiophene with diols. Initially obtained from 3,4-dibromothiophene, 3,4-dimethoxythiophene can be prepared on a large scale using the methodology recently described by Hellberg and coworkers [117], The following scheme presents some examples of ProDOT analogs obtained by transetherification [118-124]. 

S3mthesis of dimethyl 2-(vinylo)y)ethylphosphonate by transetherification catal) ed by a palladium salt. 

Zinc s. under Og Mercuric acetate Vinyl ethers by transetherification... 

The dithia-analog of EDOS, 3,4-ethylenedithioselenophene (EDTS) could be prepared by transetherification of 3,4-dimethoxyselenophene with 1, 2-ethanedithiol. The homopolymer, PEDTS, was synthesized electrochemi-cally and by solid-state oxidative polymerization. PEDTS has a significantly... 

The reaction proceeds in polar aprotic solvents (DMF, DMSO, MeCN) over a wide range of temperature (20—150° C). As a rule, the yields of the obtained products are good. However, under the same conditions, the yield of N-(silatranylmethyl)phthalimide 34 is significantly lower than that of N-(triethoxysilylmethyl) phthalimide 33 (19% and 51%, respectively). This is indicative of the decreased reactivity of compound 34 as compared with 33. It should be noted that silatrane 34 is obtained by transetherification of N-(trimethoxysilylmethyl)phthalimide 49 with triethanolamine in a yield of 59% (61). Compound 49 has been synthesized by reaction of the phthalimide sodium salt with ClCH2Si(OMe)3 (Scheme 24.5). 

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